Naomi 1/CvS1 Intermittent boot

OldFoo · Post by **OldFoo** » Sat Jun 16, 2012 1:47 pm

I just picked up a Naomi 1/Capcom IO/CvS1 in a Capcom CPS1 conversion cab. The system will always shows a Naomi splash screen and make it to the game's import warning screen, but will only intermittently boot the game. Normally, I'll get either a black screen or it will reboot, occasionally it will die after the initial game logo screen or after character select. When it does make it to the actual game, it's solid until I turn the game off. I've pulled the boards apart and cleaned them out, including gingerly cleaning the game board's pins with a toothbrush and alcohol. Nothing looks burned, no headers cracked, no caps swelled or funky looking. The boards weren't really that dirty in the first place. Voltage at the Naomi CPU connector is 3.28, 5.1 and 12.37, respectively and multiple RAM and ROM tests have been positive in test mode. I cleared the EEPROMs at the NAOMI and game levels and swapped to a second known good PSU just in case, but nothing changed. All connectors have been reset through the troubleshooting process. Based on what I've read, I'm thinking there could be a through-hole issue at the game boards pins.

I'm a newbie in the Naomi world, but I've got lots of experience in board repair on pins.

Does anyone have any thoughts?

BTW - this is a great forum! Sites like this have taught me so much and help keep the hobby alive - keep up the great work!

OldFoo · Post by **OldFoo** » Sat Jun 16, 2012 9:52 pm

if your 3.3v is adjustable I'd turn that up a tiny bit. My NAOMI used to crash like that at character select if the 3.3v was low.

OldFoo · Post by **OldFoo** » Sat Jun 16, 2012 9:58 pm

As far as I can tell, I can't see a way to adjust any voltages at the Capcom IO board. I'd be happy to rebuild the 3.3v section of the IO board if there is a chance that it would help bring the voltage up a hair, but I'll need to scratch up a schematic for the board before I dig in too much. That is a pretty common thing on pinball power supplies, so I'd be like a duck to water rebuilding that portion. It's the surface mount stuff that scares me!

OldFoo · Post by **OldFoo** » Sun Jun 17, 2012 2:25 am

Ah, yeah, no way to adjust it on the capcom I/O, it does the voltage conversion internally. I ended up getting a SUN PSU for the NAOMI itself, and haven't had any crashes since.