... I am back at this issue 4 years later, mostly thanks to
this thread
Here's what I found:
The issue appears to be directly linked to the 3.3V:
Measured at the filter board:
- if it is very low at 3.0, it goes to load the game (cart virtua tennis) and I get a "jamma i/o board not found" message. The jvs service / test buttons don't work nor the filter board buttons (I've tried 3 filter boards, working on other naomis)
- if it's low at 3.1, it goes in the test page and stays there. The jvs service / test buttons don't work nor the filter board buttons (I've tried 3 filter boards, working on other naomis)
- at 3.28, it goes to the test mode for 3 seconds and reboots. NOTE THAT THE BIOS SAYS
JAPAN NOW?!
- at 3.3 I get an "invalid format" on the screen / black screen.
so my questions for the experts : What would be responsible for handling the I/O that would be so sensible to the 3.3v? could it be caps?!
thanks!
EDIT: and I will be damned, for the kicks after posting this I thought, and If I go above 3.3 what happens?! at
3.42 THE GAME LOADS AND I CAN PLAY IT! WTF!!