First 4 bytes of prog memory won't program

[pfournier]

I have a certain number of boards with PIC18f87J50 chips that for some reason will not program the first 4 bytes of the program memory. They always read FF. I am using:

ICD-U64
Rev 1
Product ID 193
Firmware 2.92
Software 4.036

I've gotten about 8 of these so far. I've never had this happen before.

Any clues?
_________________
-Pete

[temtronic]

If you're trying to program the same,identical program into every PIC, I might think it's a production batch failure ??? Under the PIC type on the chip will be the production onfo ( batch and date), in itty bitty microfont...

Obvious test would be to cut a simple 'Hello World' program and see if that programs fine into the 'suspect' PICS.

[Ttelmah]

I have to say there do seem to be some recent batches of very 'suspect' PIC's floating around.
Just had 100 18F2550's, which triggered brownout failures at 4.95v on the 4.6v setting....

Best Wishes

[pfournier]

We are looking into the possibility of a datecode issue. I'll let you know what I find.
_________________
-Pete