User Fails to write .hex files to PIC18F452 Products

[amfortas]

Hi,
A colleague in the USA periodically fails to write my .hex files to his product. When I load the .hex into many versions of this product and all through development there are no problems.
His MikroProg Suite for PIC[v2.00] displays an identical data to mine and the programmer verifies on every attempt but only occasionally does the program run.
It appears the PIC settings are not being loaded correctly ?

Another odd feature is that whether the .hex write works is which of a number of Texas MRD2 devices is installed on his product PCB. This makes me envisage an initialisation problem if some MRD2 devices draw a higher current than others on switch-on and depresses the uP 5v supply over the 500ms time allowed. However increasing this to 2 secs does not eliminate the problem.

The Programmer is about 15yrs old and perhaps I should request an upgrade, but I cannot explain this frustrating difficulty.

Can anyone suggest what might be going wrong ?

[filip]

Hi,

Can you please attach detailed schematics and photos of your hardware ?
Have you tried some other MCU maybe ?

Regards,
Filip.