> At the company I work for we primarily make PCI-bus PC cards and software
to
> control them (most are designed for Videoconferencing).
>
> We have recently received a significant number of field failures with a
> strange (to us anyway) failure mode.


I'd strongly suspect

1)    ESD
2)    Customer practice or equipment.

ESD may be in the handling area - perhaps incoming inspection. If this is a
sudden problem, have they got a new carpet or moved to a new facility
recently. Do they have proper ESD handling procedures in place. Does the
cleaner open the mail? :-)

IF power supplies are suspect you could consider bullet proof protection on
the supplies. A close rated 3 watt zener on each supply rail to ground is a
good start. A transzorb is faster. A zener that fails under high power
overload will almost invariably go short thereby protecting other devices
(but not the power supply :-) ). Brute force crowbar protection of this sort
is not elegant but could well prove a point.

Are there any disaffected employees who have not been laid off sabotaging
the product ? :-)



        Russell McMahon

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