Max/232 Bootloader problems - Schematic attached...

[rossfree]

Hi all,

I've struggled alone on this for long enough. I've bread-boarded the MAX232 circuit with the 16f876 and it works... but once on my circuit board it does not. This is a new board, all chips socketed except the thermocouple amplifier.

The only socketed components currently on the board are the MAX232 and the 16f876. Nothing else.

The 876 has been loaded (on the breadboard) with a "blink" program and it works.

I am using Picbasic Pro and Microcode Studio. I am also swapping the MAX and 876 between the new circuit board and a breadboard. So those two components are not bad.

Could there be some suttle difference in my circuit board that I'm not finding?

Please let me know if you see something I do not. I designed this circuit board but I am an AMATEUR. I did my best. The board also uses a 16f88 (also socketed). I left off a pull-up resistor on MCLR for that chip... it will be rectified later.

I'm getting a "reset controller" message when I try to bootload to the 876 on my new circuit board. Using the same computer, program, processor and Max232 on my breadboard... it all works. Go figure!

Hope you have some suggestions.

Many thanks!

Ross