Is anyone having reliability problems with the RCM3720?
We have used several hundred RCM3720s in a product we build. After a
few days to a few months the RCM3720 will lose the ability to connect
via Ethernet, the on board Ethernet controller gets hot and the
RCM3720 will not respond even to RFU.exe when we get the product back
from the field.
The RCM3720 operates in a benign environment: Sealed enclosure, 25C
ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed to
the outside world. All internal I/O circuitry interfacing with the
RCM3720 is 3.3V logic.
Our failure rate is approaching 10% of units shipped. Invariably it is
the RCM3720; once replaced the FPGA and 74HC series logic constituting
the rest of the circuit runs flawlessly.
Mariss Freimanis
Geckodrive Inc.
RCM3720 Reliabilty Issues
Started by ●August 6, 2007
Reply by ●August 7, 20072007-08-07
I had similar problems with a few years ago with the RCM3400. I had
it all in a seal box with a 20w switch mode power supply on my own
PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP to
serial converter. I found that once they were installed they over
heated and seem to loose TCP/IP connection. They were installed high
up in the room where there was a lot of heat from lights and crowds
of peope below. The PIC's never crashed but once the ambient temp
got to about 25c the rabbit got to hot inside the box.
I solved the problem by squeezing in a realy small DC fan to direct
air onto the rabbit. They don't seem like the heat !
--- In r..., "Mariss Freimanis"
wrote:
>
> Is anyone having reliability problems with the RCM3720?
>
> We have used several hundred RCM3720s in a product we build. After a
> few days to a few months the RCM3720 will lose the ability to
connect
> via Ethernet, the on board Ethernet controller gets hot and the
> RCM3720 will not respond even to RFU.exe when we get the product
back
> from the field.
>
> The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
to
> the outside world. All internal I/O circuitry interfacing with the
> RCM3720 is 3.3V logic.
>
> Our failure rate is approaching 10% of units shipped. Invariably it
is
> the RCM3720; once replaced the FPGA and 74HC series logic
constituting
> the rest of the circuit runs flawlessly.
>
> Mariss Freimanis
> Geckodrive Inc.
>
it all in a seal box with a 20w switch mode power supply on my own
PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP to
serial converter. I found that once they were installed they over
heated and seem to loose TCP/IP connection. They were installed high
up in the room where there was a lot of heat from lights and crowds
of peope below. The PIC's never crashed but once the ambient temp
got to about 25c the rabbit got to hot inside the box.
I solved the problem by squeezing in a realy small DC fan to direct
air onto the rabbit. They don't seem like the heat !
--- In r..., "Mariss Freimanis"
wrote:
>
> Is anyone having reliability problems with the RCM3720?
>
> We have used several hundred RCM3720s in a product we build. After a
> few days to a few months the RCM3720 will lose the ability to
connect
> via Ethernet, the on board Ethernet controller gets hot and the
> RCM3720 will not respond even to RFU.exe when we get the product
back
> from the field.
>
> The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
to
> the outside world. All internal I/O circuitry interfacing with the
> RCM3720 is 3.3V logic.
>
> Our failure rate is approaching 10% of units shipped. Invariably it
is
> the RCM3720; once replaced the FPGA and 74HC series logic
constituting
> the rest of the circuit runs flawlessly.
>
> Mariss Freimanis
> Geckodrive Inc.
>
Reply by ●August 7, 20072007-08-07
Thank you for the reply. I'm not sure it can be heat related in this
case:
1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
dissipates 1.61 Watts leaving 1.15 Watts for the entire circuit.
2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
178mm). The measured temperature rise is 2.8C on the package surface,
the measured internal temperature rise is 3.6C above ambient.
3) The RCM3720 thermal "exclusion zone" requirements have been followed.
4) The RCM3720 is rated for operation at a 70C ambient. It sees a
maximum ambient of 44C inside the package (for 40C external).
5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
The refuse to flash with either RFU.exe or Flashit.exe on initial
installation.
The Rabbits are terrific little modules at a great price and we are
otherwise very pleased with them. I have to assume we are doing
something wrong to have these problems. I would like to know what it
may be.
Mariss
Below is a sample of failed RCM3720s
---------------
01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
02. CE84C1 RFU "Error reading bytes". Initial failure.
03. CE84C3 RFU "Flash parameters not found". Initial failure.
04. CE84B7 RFU "No Rabbit detected". Field failure.
05. CE84C4 Same as (02). Field failure.
06. CE8416 Same as (03). Field failure.
07. CE95FF Flashes OK. No Ethernet. Field failure.
08. C8C1DF RFU "Target comm error". Initial failure.
09. CBBFF2 Flashes OK. Port A failed. Field failure.
10. CBBEC5 Same as (09). Field failure.
11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
In all cases replacing the RCM3720 fixed the problem. There were no
problems with the rest of the hardware.
--- In r..., "neil2452" wrote:
>
> I had similar problems with a few years ago with the RCM3400. I had
> it all in a seal box with a 20w switch mode power supply on my own
> PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP to
> serial converter. I found that once they were installed they over
> heated and seem to loose TCP/IP connection. They were installed high
> up in the room where there was a lot of heat from lights and crowds
> of peope below. The PIC's never crashed but once the ambient temp
> got to about 25c the rabbit got to hot inside the box.
>
> I solved the problem by squeezing in a realy small DC fan to direct
> air onto the rabbit. They don't seem like the heat !
> --- In r..., "Mariss Freimanis"
> wrote:
> >
> > Is anyone having reliability problems with the RCM3720?
> >
> > We have used several hundred RCM3720s in a product we build. After a
> > few days to a few months the RCM3720 will lose the ability to
> connect
> > via Ethernet, the on board Ethernet controller gets hot and the
> > RCM3720 will not respond even to RFU.exe when we get the product
> back
> > from the field.
> >
> > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> to
> > the outside world. All internal I/O circuitry interfacing with the
> > RCM3720 is 3.3V logic.
> >
> > Our failure rate is approaching 10% of units shipped. Invariably it
> is
> > the RCM3720; once replaced the FPGA and 74HC series logic
> constituting
> > the rest of the circuit runs flawlessly.
> >
> > Mariss Freimanis
> > Geckodrive Inc.
>
1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
dissipates 1.61 Watts leaving 1.15 Watts for the entire circuit.
2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
178mm). The measured temperature rise is 2.8C on the package surface,
the measured internal temperature rise is 3.6C above ambient.
3) The RCM3720 thermal "exclusion zone" requirements have been followed.
4) The RCM3720 is rated for operation at a 70C ambient. It sees a
maximum ambient of 44C inside the package (for 40C external).
5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
The refuse to flash with either RFU.exe or Flashit.exe on initial
installation.
The Rabbits are terrific little modules at a great price and we are
otherwise very pleased with them. I have to assume we are doing
something wrong to have these problems. I would like to know what it
may be.
Mariss
Below is a sample of failed RCM3720s
---------------
01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
02. CE84C1 RFU "Error reading bytes". Initial failure.
03. CE84C3 RFU "Flash parameters not found". Initial failure.
04. CE84B7 RFU "No Rabbit detected". Field failure.
05. CE84C4 Same as (02). Field failure.
06. CE8416 Same as (03). Field failure.
07. CE95FF Flashes OK. No Ethernet. Field failure.
08. C8C1DF RFU "Target comm error". Initial failure.
09. CBBFF2 Flashes OK. Port A failed. Field failure.
10. CBBEC5 Same as (09). Field failure.
11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
In all cases replacing the RCM3720 fixed the problem. There were no
problems with the rest of the hardware.
--- In r..., "neil2452" wrote:
>
> I had similar problems with a few years ago with the RCM3400. I had
> it all in a seal box with a 20w switch mode power supply on my own
> PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP to
> serial converter. I found that once they were installed they over
> heated and seem to loose TCP/IP connection. They were installed high
> up in the room where there was a lot of heat from lights and crowds
> of peope below. The PIC's never crashed but once the ambient temp
> got to about 25c the rabbit got to hot inside the box.
>
> I solved the problem by squeezing in a realy small DC fan to direct
> air onto the rabbit. They don't seem like the heat !
> --- In r..., "Mariss Freimanis"
> wrote:
> >
> > Is anyone having reliability problems with the RCM3720?
> >
> > We have used several hundred RCM3720s in a product we build. After a
> > few days to a few months the RCM3720 will lose the ability to
> connect
> > via Ethernet, the on board Ethernet controller gets hot and the
> > RCM3720 will not respond even to RFU.exe when we get the product
> back
> > from the field.
> >
> > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> to
> > the outside world. All internal I/O circuitry interfacing with the
> > RCM3720 is 3.3V logic.
> >
> > Our failure rate is approaching 10% of units shipped. Invariably it
> is
> > the RCM3720; once replaced the FPGA and 74HC series logic
> constituting
> > the rest of the circuit runs flawlessly.
> >
> > Mariss Freimanis
> > Geckodrive Inc.
>
Reply by ●August 7, 20072007-08-07
Would the latest (failing) ones be the Lead-Free versions (red PCB)?
-Pete
-----Original Message-----
From: r... [mailto:r...]
On Behalf Of Mariss Freimanis
Sent: Tuesday, August 07, 2007 12:04 PM
To: r...
Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
Thank you for the reply. I'm not sure it can be heat related in this
case:
1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator dissipates
1.61 Watts leaving 1.15 Watts for the entire circuit.
2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by 178mm).
The measured temperature rise is 2.8C on the package surface, the
measured internal temperature rise is 3.6C above ambient.
3) The RCM3720 thermal "exclusion zone" requirements have been followed.
4) The RCM3720 is rated for operation at a 70C ambient. It sees a
maximum ambient of 44C inside the package (for 40C external).
5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
The refuse to flash with either RFU.exe or Flashit.exe on initial
installation.
The Rabbits are terrific little modules at a great price and we are
otherwise very pleased with them. I have to assume we are doing
something wrong to have these problems. I would like to know what it may
be.
Mariss
Below is a sample of failed RCM3720s
---------------
01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
02. CE84C1 RFU "Error reading bytes". Initial failure.
03. CE84C3 RFU "Flash parameters not found". Initial failure.
04. CE84B7 RFU "No Rabbit detected". Field failure.
05. CE84C4 Same as (02). Field failure.
06. CE8416 Same as (03). Field failure.
07. CE95FF Flashes OK. No Ethernet. Field failure.
08. C8C1DF RFU "Target comm error". Initial failure.
09. CBBFF2 Flashes OK. Port A failed. Field failure.
10. CBBEC5 Same as (09). Field failure.
11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
In all cases replacing the RCM3720 fixed the problem. There were no
problems with the rest of the hardware.
--- In r..., "neil2452" wrote:
>
> I had similar problems with a few years ago with the RCM3400. I had
> it all in a seal box with a 20w switch mode power supply on my own PCB
> with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> converter. I found that once they were installed they over heated and
> seem to loose TCP/IP connection. They were installed high up in the
> room where there was a lot of heat from lights and crowds of peope
> below. The PIC's never crashed but once the ambient temp got to about
> 25c the rabbit got to hot inside the box.
>
> I solved the problem by squeezing in a realy small DC fan to direct
> air onto the rabbit. They don't seem like the heat !
> --- In r..., "Mariss Freimanis"
> wrote:
> >
> > Is anyone having reliability problems with the RCM3720?
> >
> > We have used several hundred RCM3720s in a product we build. After a
> > few days to a few months the RCM3720 will lose the ability to
> connect
> > via Ethernet, the on board Ethernet controller gets hot and the
> > RCM3720 will not respond even to RFU.exe when we get the product
> back
> > from the field.
> >
> > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> to
> > the outside world. All internal I/O circuitry interfacing with the
> > RCM3720 is 3.3V logic.
> >
> > Our failure rate is approaching 10% of units shipped. Invariably it
> is
> > the RCM3720; once replaced the FPGA and 74HC series logic
> constituting
> > the rest of the circuit runs flawlessly.
> >
> > Mariss Freimanis
> > Geckodrive Inc.
>
Yahoo! Groups Links
-Pete
-----Original Message-----
From: r... [mailto:r...]
On Behalf Of Mariss Freimanis
Sent: Tuesday, August 07, 2007 12:04 PM
To: r...
Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
Thank you for the reply. I'm not sure it can be heat related in this
case:
1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator dissipates
1.61 Watts leaving 1.15 Watts for the entire circuit.
2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by 178mm).
The measured temperature rise is 2.8C on the package surface, the
measured internal temperature rise is 3.6C above ambient.
3) The RCM3720 thermal "exclusion zone" requirements have been followed.
4) The RCM3720 is rated for operation at a 70C ambient. It sees a
maximum ambient of 44C inside the package (for 40C external).
5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
The refuse to flash with either RFU.exe or Flashit.exe on initial
installation.
The Rabbits are terrific little modules at a great price and we are
otherwise very pleased with them. I have to assume we are doing
something wrong to have these problems. I would like to know what it may
be.
Mariss
Below is a sample of failed RCM3720s
---------------
01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
02. CE84C1 RFU "Error reading bytes". Initial failure.
03. CE84C3 RFU "Flash parameters not found". Initial failure.
04. CE84B7 RFU "No Rabbit detected". Field failure.
05. CE84C4 Same as (02). Field failure.
06. CE8416 Same as (03). Field failure.
07. CE95FF Flashes OK. No Ethernet. Field failure.
08. C8C1DF RFU "Target comm error". Initial failure.
09. CBBFF2 Flashes OK. Port A failed. Field failure.
10. CBBEC5 Same as (09). Field failure.
11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
In all cases replacing the RCM3720 fixed the problem. There were no
problems with the rest of the hardware.
--- In r..., "neil2452" wrote:
>
> I had similar problems with a few years ago with the RCM3400. I had
> it all in a seal box with a 20w switch mode power supply on my own PCB
> with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> converter. I found that once they were installed they over heated and
> seem to loose TCP/IP connection. They were installed high up in the
> room where there was a lot of heat from lights and crowds of peope
> below. The PIC's never crashed but once the ambient temp got to about
> 25c the rabbit got to hot inside the box.
>
> I solved the problem by squeezing in a realy small DC fan to direct
> air onto the rabbit. They don't seem like the heat !
> --- In r..., "Mariss Freimanis"
> wrote:
> >
> > Is anyone having reliability problems with the RCM3720?
> >
> > We have used several hundred RCM3720s in a product we build. After a
> > few days to a few months the RCM3720 will lose the ability to
> connect
> > via Ethernet, the on board Ethernet controller gets hot and the
> > RCM3720 will not respond even to RFU.exe when we get the product
> back
> > from the field.
> >
> > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> to
> > the outside world. All internal I/O circuitry interfacing with the
> > RCM3720 is 3.3V logic.
> >
> > Our failure rate is approaching 10% of units shipped. Invariably it
> is
> > the RCM3720; once replaced the FPGA and 74HC series logic
> constituting
> > the rest of the circuit runs flawlessly.
> >
> > Mariss Freimanis
> > Geckodrive Inc.
>
Yahoo! Groups Links
Reply by ●August 7, 20072007-08-07
I read elsewhere in this group that there have been reliability
issues with the RoHS changes. It is very possible that the no-lead
reflow solder is marginal and develops bad joints over time or after
the boards have been flexed during insertions / extractions on the
user boards. We've seen quite a few DOAs with the RCM37xx modules
(all red boards), also, but we haven't sold enough product at this
point to know if there are any field failures. Our beta units have
held up well, but most of them are mounted in the open in air
conditioned areas (no enclosures).
--- In r..., "Mariss Freimanis"
wrote:
>
> Thank you for the reply. I'm not sure it can be heat related in
this case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
> dissipates 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
> 178mm). The measured temperature rise is 2.8C on the package
surface,
> the measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been
followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it
> may be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field
failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
>
>
> --- In r..., "neil2452"
wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I
had
> > it all in a seal box with a 20w switch mode power supply on my
own
> > PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP
to
> > serial converter. I found that once they were installed they
over
> > heated and seem to loose TCP/IP connection. They were installed
high
> > up in the room where there was a lot of heat from lights and
crowds
> > of peope below. The PIC's never crashed but once the ambient
temp
> > got to about 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to
direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r..., "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build.
After a
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the
product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure,
25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is
exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with
the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped.
Invariably it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
>
issues with the RoHS changes. It is very possible that the no-lead
reflow solder is marginal and develops bad joints over time or after
the boards have been flexed during insertions / extractions on the
user boards. We've seen quite a few DOAs with the RCM37xx modules
(all red boards), also, but we haven't sold enough product at this
point to know if there are any field failures. Our beta units have
held up well, but most of them are mounted in the open in air
conditioned areas (no enclosures).
--- In r..., "Mariss Freimanis"
wrote:
>
> Thank you for the reply. I'm not sure it can be heat related in
this case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
> dissipates 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
> 178mm). The measured temperature rise is 2.8C on the package
surface,
> the measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been
followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it
> may be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field
failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
>
>
> --- In r..., "neil2452"
wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I
had
> > it all in a seal box with a 20w switch mode power supply on my
own
> > PCB with about 9 PIC's on it. The rabbit was effectly a TCP/IP
to
> > serial converter. I found that once they were installed they
over
> > heated and seem to loose TCP/IP connection. They were installed
high
> > up in the room where there was a lot of heat from lights and
crowds
> > of peope below. The PIC's never crashed but once the ambient
temp
> > got to about 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to
direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r..., "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build.
After a
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the
product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure,
25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is
exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with
the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped.
Invariably it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
>
Reply by ●August 7, 20072007-08-07
Mariss,
Please contact Technical Support or your Salesperson and we would be
happy to work with you on the issues you are seeing.
Thanks
Joel Baumert
Director, Engineering
--- In r..., "Mariss Freimanis"
wrote:
>
> Is anyone having reliability problems with the RCM3720?
>
> We have used several hundred RCM3720s in a product we build. After a
> few days to a few months the RCM3720 will lose the ability to
connect
> via Ethernet, the on board Ethernet controller gets hot and the
> RCM3720 will not respond even to RFU.exe when we get the product
back
> from the field.
>
> The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
to
> the outside world. All internal I/O circuitry interfacing with the
> RCM3720 is 3.3V logic.
>
> Our failure rate is approaching 10% of units shipped. Invariably it
is
> the RCM3720; once replaced the FPGA and 74HC series logic
constituting
> the rest of the circuit runs flawlessly.
>
> Mariss Freimanis
> Geckodrive Inc.
>
Please contact Technical Support or your Salesperson and we would be
happy to work with you on the issues you are seeing.
Thanks
Joel Baumert
Director, Engineering
--- In r..., "Mariss Freimanis"
wrote:
>
> Is anyone having reliability problems with the RCM3720?
>
> We have used several hundred RCM3720s in a product we build. After a
> few days to a few months the RCM3720 will lose the ability to
connect
> via Ethernet, the on board Ethernet controller gets hot and the
> RCM3720 will not respond even to RFU.exe when we get the product
back
> from the field.
>
> The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
to
> the outside world. All internal I/O circuitry interfacing with the
> RCM3720 is 3.3V logic.
>
> Our failure rate is approaching 10% of units shipped. Invariably it
is
> the RCM3720; once replaced the FPGA and 74HC series logic
constituting
> the rest of the circuit runs flawlessly.
>
> Mariss Freimanis
> Geckodrive Inc.
>
Reply by ●August 7, 20072007-08-07
Numbers 01 thru 07 are RoHS compliant modules. Numbers 08 thru 11 are
the green, non-RoHS boards.
Visual inspection with a microscope reveals no problems associated
with lead-free solder such as poor wetting of joints, fractured solder
or tin dendrite growth.
Mariss
--- In r..., "Fournier, Pete"
wrote:
>
> Would the latest (failing) ones be the Lead-Free versions (red PCB)?
> -Pete
>
> -----Original Message-----
> From: r... [mailto:r...]
> On Behalf Of Mariss Freimanis
> Sent: Tuesday, August 07, 2007 12:04 PM
> To: r...
> Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
>
> Thank you for the reply. I'm not sure it can be heat related in this
> case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator dissipates
> 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by 178mm).
> The measured temperature rise is 2.8C on the package surface, the
> measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it may
> be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
>
>
> --- In r..., "neil2452" wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I had
> > it all in a seal box with a 20w switch mode power supply on my own PCB
>
> > with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> > converter. I found that once they were installed they over heated and
>
> > seem to loose TCP/IP connection. They were installed high up in the
> > room where there was a lot of heat from lights and crowds of peope
> > below. The PIC's never crashed but once the ambient temp got to about
>
> > 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r..., "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build. After a
>
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped. Invariably it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
> >
>
> Yahoo! Groups Links
>
the green, non-RoHS boards.
Visual inspection with a microscope reveals no problems associated
with lead-free solder such as poor wetting of joints, fractured solder
or tin dendrite growth.
Mariss
--- In r..., "Fournier, Pete"
wrote:
>
> Would the latest (failing) ones be the Lead-Free versions (red PCB)?
> -Pete
>
> -----Original Message-----
> From: r... [mailto:r...]
> On Behalf Of Mariss Freimanis
> Sent: Tuesday, August 07, 2007 12:04 PM
> To: r...
> Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
>
> Thank you for the reply. I'm not sure it can be heat related in this
> case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator dissipates
> 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by 178mm).
> The measured temperature rise is 2.8C on the package surface, the
> measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it may
> be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
>
>
> --- In r..., "neil2452" wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I had
> > it all in a seal box with a 20w switch mode power supply on my own PCB
>
> > with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> > converter. I found that once they were installed they over heated and
>
> > seem to loose TCP/IP connection. They were installed high up in the
> > room where there was a lot of heat from lights and crowds of peope
> > below. The PIC's never crashed but once the ambient temp got to about
>
> > 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r..., "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build. After a
>
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure, 25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped. Invariably it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
> >
>
> Yahoo! Groups Links
>
Reply by ●August 7, 20072007-08-07
I assume the problematic core modules do work, aside from the
Ethernet-related failure you are seeing. If you have not already, you
should give special attention to the solder connections on the Ethernet
connectors. If any of them appear to be disconnected, or if the
connector is a loose that could be the culprit.
Also, are you noticing these issues with units that were manufactured
around a particular time period?
Omid
________________________________
From: r... [mailto:r...]
On Behalf Of Mariss Freimanis
Sent: Tuesday, August 07, 2007 10:17 AM
To: r...
Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
Numbers 01 thru 07 are RoHS compliant modules. Numbers 08 thru 11 are
the green, non-RoHS boards.
Visual inspection with a microscope reveals no problems associated
with lead-free solder such as poor wetting of joints, fractured solder
or tin dendrite growth.
Mariss
--- In r...
, "Fournier, Pete"
wrote:
>
> Would the latest (failing) ones be the Lead-Free versions (red PCB)?
> -Pete
>
> -----Original Message-----
> From: r...
[mailto:r...
]
> On Behalf Of Mariss Freimanis
> Sent: Tuesday, August 07, 2007 12:04 PM
> To: r...
> Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
>
> Thank you for the reply. I'm not sure it can be heat related in this
> case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
dissipates
> 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
178mm).
> The measured temperature rise is 2.8C on the package surface, the
> measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been
followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it
may
> be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
> --- In r...
, "neil2452"
wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I had
> > it all in a seal box with a 20w switch mode power supply on my own
PCB
>
> > with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> > converter. I found that once they were installed they over heated
and
>
> > seem to loose TCP/IP connection. They were installed high up in the
> > room where there was a lot of heat from lights and crowds of peope
> > below. The PIC's never crashed but once the ambient temp got to
about
>
> > 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r...
, "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build. After
a
>
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure,
25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped. Invariably
it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
> > Yahoo! Groups Links
>
Ethernet-related failure you are seeing. If you have not already, you
should give special attention to the solder connections on the Ethernet
connectors. If any of them appear to be disconnected, or if the
connector is a loose that could be the culprit.
Also, are you noticing these issues with units that were manufactured
around a particular time period?
Omid
________________________________
From: r... [mailto:r...]
On Behalf Of Mariss Freimanis
Sent: Tuesday, August 07, 2007 10:17 AM
To: r...
Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
Numbers 01 thru 07 are RoHS compliant modules. Numbers 08 thru 11 are
the green, non-RoHS boards.
Visual inspection with a microscope reveals no problems associated
with lead-free solder such as poor wetting of joints, fractured solder
or tin dendrite growth.
Mariss
--- In r...
, "Fournier, Pete"
wrote:
>
> Would the latest (failing) ones be the Lead-Free versions (red PCB)?
> -Pete
>
> -----Original Message-----
> From: r...
[mailto:r...
]
> On Behalf Of Mariss Freimanis
> Sent: Tuesday, August 07, 2007 12:04 PM
> To: r...
> Subject: [rabbit-semi] Re: RCM3720 Reliabilty Issues
>
> Thank you for the reply. I'm not sure it can be heat related in this
> case:
>
> 1) Input power is 230mA at 12VDC or 2.76 Watts. The regulator
dissipates
> 1.61 Watts leaving 1.15 Watts for the entire circuit.
>
> 2) The package is aluminum, 2.5" by 1.5" by 7" (63mm by 38mm by
178mm).
> The measured temperature rise is 2.8C on the package surface, the
> measured internal temperature rise is 3.6C above ambient.
>
> 3) The RCM3720 thermal "exclusion zone" requirements have been
followed.
>
> 4) The RCM3720 is rated for operation at a 70C ambient. It sees a
> maximum ambient of 44C inside the package (for 40C external).
>
> 5) 2 to 3 RCM3720's out of 100 ordered are DOA right out of the box.
> The refuse to flash with either RFU.exe or Flashit.exe on initial
> installation.
>
> The Rabbits are terrific little modules at a great price and we are
> otherwise very pleased with them. I have to assume we are doing
> something wrong to have these problems. I would like to know what it
may
> be.
>
> Mariss
>
> Below is a sample of failed RCM3720s
> ---------------
> 01. CE84AC Flashes OK. Get "TCP/IP error 735". Field failure.
> 02. CE84C1 RFU "Error reading bytes". Initial failure.
> 03. CE84C3 RFU "Flash parameters not found". Initial failure.
> 04. CE84B7 RFU "No Rabbit detected". Field failure.
> 05. CE84C4 Same as (02). Field failure.
> 06. CE8416 Same as (03). Field failure.
> 07. CE95FF Flashes OK. No Ethernet. Field failure.
> 08. C8C1DF RFU "Target comm error". Initial failure.
> 09. CBBFF2 Flashes OK. Port A failed. Field failure.
> 10. CBBEC5 Same as (09). Field failure.
> 11. CBBEC2 Flashes OK. DS1 LED 'on' w/o Ethernet cable. Field failure.
>
> In all cases replacing the RCM3720 fixed the problem. There were no
> problems with the rest of the hardware.
>
> --- In r...
, "neil2452"
wrote:
> >
> > I had similar problems with a few years ago with the RCM3400. I had
> > it all in a seal box with a 20w switch mode power supply on my own
PCB
>
> > with about 9 PIC's on it. The rabbit was effectly a TCP/IP to serial
> > converter. I found that once they were installed they over heated
and
>
> > seem to loose TCP/IP connection. They were installed high up in the
> > room where there was a lot of heat from lights and crowds of peope
> > below. The PIC's never crashed but once the ambient temp got to
about
>
> > 25c the rabbit got to hot inside the box.
> >
> > I solved the problem by squeezing in a realy small DC fan to direct
> > air onto the rabbit. They don't seem like the heat !
> >
> >
> > --- In r...
, "Mariss Freimanis"
> > wrote:
> > >
> > > Is anyone having reliability problems with the RCM3720?
> > >
> > > We have used several hundred RCM3720s in a product we build. After
a
>
> > > few days to a few months the RCM3720 will lose the ability to
> > connect
> > > via Ethernet, the on board Ethernet controller gets hot and the
> > > RCM3720 will not respond even to RFU.exe when we get the product
> > back
> > > from the field.
> > >
> > > The RCM3720 operates in a benign environment: Sealed enclosure,
25C
> > > ambient, LM7805 supply regulator and no RCM3720 I/O pin is exposed
> > to
> > > the outside world. All internal I/O circuitry interfacing with the
> > > RCM3720 is 3.3V logic.
> > >
> > > Our failure rate is approaching 10% of units shipped. Invariably
it
> > is
> > > the RCM3720; once replaced the FPGA and 74HC series logic
> > constituting
> > > the rest of the circuit runs flawlessly.
> > >
> > > Mariss Freimanis
> > > Geckodrive Inc.
> > >
> > Yahoo! Groups Links
>
Reply by ●August 12, 20072007-08-12
We are beginning to notice problems with Zworld RCM3100 modules. A small
percentage, around 5% I'm told of brand new units won't accept a 300kb
program. Tend to give up half way through the program load. Given that we are
looking at using 200 per month this is very bad news. Has anyone else come
across this problem.
Alan Matheson
Alan Matheson
Reply by ●August 12, 20072007-08-12
You need answers from Zworld I think. The questions I would be
asking
are what Q&A procedures are they using, and what testing is happening
to the product before it is shipped.
When I used to work with Lucas some years ago each and every ECU unit
they made would go through a burn in test. This was literally
running the boards in an oven for several hours hooked up to a peice
of ATE that simulated the car and checked for the correct operation
of all the I/O pins. We made ATE (Automatic Test Equipment) for
them.
As an example of PCB assembly yeild rates I have just had about 250
not too sophisticated SMT PIC circuits built in LeadFree. I had 25
out of the batch that failed on my test rig. Most fail due to simple
faults like bridged pins, or toomstoning, or occasionaly missing
componenets. The raw PCBs should normally have gone through an
automatic bare board test so there should be less to worry about
there. Also I can't remember the last time I had duff chip from a
semiconductor manufacturer so I am sure they do rigourous QA and
testing. I think you have a bigger chance of winning the lotto than
finding a new duff part from them.
The RCM modules I would think are quite deemanding circuits to build
given a multilayer PCB design and the realy small components they use
and now LeadFree (Why are we crazey about not using lead solder in
europe, I bet theres more lead on are church roofs than in our tv's
etc). If they just drop the boards in a box as they roll off the end
of the line then duff boards will be shipped for sure. However if
are they are doing a proper burnin test with ATE that checks
everything then how can they explain your 5% failure rate ? Perhaps
the answer is somewhere between the two.
Regards
Neil
--- In r..., "Alan Matheson"
wrote:
>
> We are beginning to notice problems with Zworld RCM3100 modules. A
small percentage, around 5% I'm told of brand new units won't accept
a
300kb program. Tend to give up half way through the program load.
Given that we are looking at using 200 per month this is very bad
news.
Has anyone else come across this problem.
> Alan Matheson
>
asking
are what Q&A procedures are they using, and what testing is happening
to the product before it is shipped.
When I used to work with Lucas some years ago each and every ECU unit
they made would go through a burn in test. This was literally
running the boards in an oven for several hours hooked up to a peice
of ATE that simulated the car and checked for the correct operation
of all the I/O pins. We made ATE (Automatic Test Equipment) for
them.
As an example of PCB assembly yeild rates I have just had about 250
not too sophisticated SMT PIC circuits built in LeadFree. I had 25
out of the batch that failed on my test rig. Most fail due to simple
faults like bridged pins, or toomstoning, or occasionaly missing
componenets. The raw PCBs should normally have gone through an
automatic bare board test so there should be less to worry about
there. Also I can't remember the last time I had duff chip from a
semiconductor manufacturer so I am sure they do rigourous QA and
testing. I think you have a bigger chance of winning the lotto than
finding a new duff part from them.
The RCM modules I would think are quite deemanding circuits to build
given a multilayer PCB design and the realy small components they use
and now LeadFree (Why are we crazey about not using lead solder in
europe, I bet theres more lead on are church roofs than in our tv's
etc). If they just drop the boards in a box as they roll off the end
of the line then duff boards will be shipped for sure. However if
are they are doing a proper burnin test with ATE that checks
everything then how can they explain your 5% failure rate ? Perhaps
the answer is somewhere between the two.
Regards
Neil
--- In r..., "Alan Matheson"
wrote:
>
> We are beginning to notice problems with Zworld RCM3100 modules. A
small percentage, around 5% I'm told of brand new units won't accept
a
300kb program. Tend to give up half way through the program load.
Given that we are looking at using 200 per month this is very bad
news.
Has anyone else come across this problem.
> Alan Matheson
>
