Thanks Boots
i've checked most those, even rebuilt the reset section of the board - tested the boot voltage on U9 and it seems to be fine. I dont think its a reset relate issue.
Is there any way to verify the program rom? ie can i read-out the chip contents and verify against an online bin file somewhere?
I have noticed that the VMA voltage on U9 is too high, so if i was a betting man i'd suggest the issue lies therein...
Check U9 Pin 5. This is the VMA line. It is a pulsing signal and reads about 2.8v with a DMM. If incorrect first try a new U9. Next check U14D, U15C, U19B. U15 is the most likely IC to have failed.
A legible M200 Schematic would be of help- those available on the net are very poor quality