Hello,

My name is Robert and I'm here in Arizona programming a control board (PIC18F8723) for a high voltage refrigeration application. Things have been going fine for months programming and reprogramming, but today the melabs Programmer crashed on me for the first time right in the middle of programming. As I have never had that problem before, it leads me to believe this was the cause. After restarting the programmer, I attempted to program again and

it programmed and verified, but nothing came up on my output screen, nor did my test LEDs on the board do their startup sequence.

I shutdown the board and tried to program again with the same result. I tried an older version of my code, with still the same result. Testing of the connections between the processor and the screen seem fine. So I pulled out the backup board and plugged it in. An older version of the code that was on that backup board popped up on screen and appeared to work just fine. So I programmed it with the new code only to see it fall into the same pit of not starting after programming and verifying. Programming the old code back to the old board still proved unfruitful. The boards appear to be getting power. I tried another U2 programmer as well and still the same result.Short of testing more of the hundreds of tiny connections, I'm not sure what would be the next step in diagnosing this problem. There was no change to the setup file before the problem started, it must be something to do with the crash of the programmer, but then why would the second board program, verify and then have the same symptoms without the crash of the programmer.

What would you do next to diagnose the problem?