Chip failure

Neutone · Joined: 08 Sep 2003 Posts: 839 Location: Houston

I had a circuit returned from the field recently. The circuit uses a REF02 to supply 5 volts to a wire wound pot. The tap goes to the PIC. The program memory was partly erased. On first inspection I could find nothing to indicate the cause of failure. I was told that the board failed during a lighting storm. I was thinking maybe the pot had an induced voltage and caused the failure. I know it's reaching but I cant think of anything else. None of the componants show signs of damage except the partly erased PIC.

Haplo · Joined: 06 Sep 2003 Posts: 659 Location: Sydney, Australia

This is very similar to the problem that I have experienced many times with CCS ICDU-40. The code in the 18F252 chip inside the ICD gets erased. None of the components show any sign of damage. When I burn the ICD firmware back to it (using an ICDS) it comes back to life for a while, and dies after a few more days.

Are you using the same PIC by any chance? I hope this mystery gets solved soon. I can live with ICD losing code (although it is very inconvenient), but I can't afford any of my boards doing so out in the field.