What is this BS Castle is feeding this customer?

[Pdelcast]

WELL, nice of everyone to keep everybody else honest. :)


HERE IS THE STATUS of our investigation.

1. It seems to be an infant mortality problem with the switcher control chip, a National Semiconductor LM3485
2. There is already a TVS (transient voltage suppressor) on the circuit that feeds the LM3485 -- so it may NOT be a voltage spike related failure (28V TVS on LM3485 power line, LM3485 part is rated to 36V operational,) but we are not ruling out the possibility at this time.

We are working with National Semiconductor to determine the cause of the failures. It seems that making a couple minor changes to the circuit make everything work fine -- but we haven't determined the cause of the failures yet.

Patrick