If I remember my electronics courses correctly, timing circuits are affected not linearly by temperature but to the 3rd or 4th power of temperature.  The Atmel chip may be completely within spec at all times (even high temp) but it's timing is off due to internal clock which a software control of timing should be able to fix.

Sevak


On Tue, 2003-07-22 at 11:22, Dan Petermann wrote:
Temperature affects all electronics to some degree or another. This is just 
a guess.
I suspect that the "bad" Amtel chips are just barely within standard 
SmartBridge specification
for that circuit. Once the unit heats up, the timing skews enough that the 
input or output
of the chip is no longer within the timing window. The end result is that 
the data cannot be
used due to it is not there when the circuit is looking for it.

Unplugging the unit will cool the chip enough to bring it back into spec. 
for a while.

I ran into situations like this working for a manufacturer of remote 
controlled spectrum
analyzers for cable TV plants (Cheetah Systems). 1 inductor from 1 
manufacturer on the
main tuner board was bad. Eliminating that 1 part jumped our output by 60%. 
If you measured
the part it was in spec., once hot it would totally screw up the filter 
response. After this
incedent ALL of the finished product went thru a 24 hour "burn in" period 
and then was
recalibrated. The RMA''s dropped to virtually zero.

Thankfully none of our IC's, FPGA's or processors had this problem.

Kudo's to the SmartBridge team for finding this. I know it must have been a 
Tylenol moment!



At 10:07 PM 7/21/2003 -0400, you wrote:
>Hello Dan,
>
>So explain why heat is affecting it?  And why the long power down
>time?
>
>Barry
>
>Monday, July 21, 2003, 7:18:10 PM, you wrote:
>
>DP> If you had read the archives you would have found out that it is not
>DP> "flaky" hardware but a timing issue.
>DP> Big difference. Amtel changed the specs of the chip and SB had to change
>DP> the firmware to compensate.
>DP> If you have been in the business as long as you say then you know that 
>this
>DP> is possible.
>
>DP> Dan Petermann
>DP> Wyoming.com
>
>
>DP> At 06:36 PM 7/21/2003 -0400, you wrote:
> >>Hello sB,
> >>
> >>This is not the response I want to see or hear about a product that is
> >>in my network. "MAGIC" is BS when the customer quits telling me they
> >>are always down.
> >>
> >>I don't believe for an instant that "firmware" is fixing an
> >>overheating issue. I was trained as an Electronics Tech and have 12
> >>plus years of fixing electronics to the board level as experience.
> >>Adding some code is not going to change a flaky component. Basically
> >>is the firmware degrading the radio operation to the point the
> >>component does not overheat?
> >>
> >>Fortunately, I only have a few SB products left in the system plus the ones
> >>in the junk box.
> >>
> >>Barry
> >>
> >>Monday, July 21, 2003, 2:05:44 PM, you wrote:
> >>
> >>sTS> I know this is hard to believe. Sometimes when you try to associate to
> >>sTS> AP that has no WEP enabled, it tell you to check the 
> authentication and
> >>sTS> WEP, try do a power cycle the unit or reboot the PC, it may work then.
> >>sTS> It is just a magic trick.
> >>
> >>
> >>
> >>sTS> Alex
> >>
> >>sTS> sB Tech Support
> >>
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>  Barry                            mailto:[EMAIL PROTECTED]
>
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