Naomi 2 Locks Up

[doop9174]

I'm sorry if this thread is redundant in any way, but I'm having trouble with one of my Naomi 2 motherboards.

When I power it up, it starts fine, but as soon as the game starts, it locks up. For instance, when starting Virtua Tennis, the game will freeze just as the Sega logo appears. All the controls and buttons become unresponsive, and I can't get into test mode. There aren't any sound or visual glitches before the lock up. The screen just freezes. This originally started a few months ago with a Virtua Tennis cartridge, but when I switched to Virtua Fighter 4, things would work normally. Now it locks up with VF4 as well.

I don't think this is an issue with the cartridges, since they work perfectly in my other Naomi 2. I checked the voltage when this issue first started and it was just barely over 5v. I can get into the test mode if I hit the test button after the Naomi boots, but before the game starts. All the RAM and ROM tests pass successfully. I'm using the multi-region BIOS, but changing the region has no effect. I also switched back to the original Japanese BIOS chip, and the problem still persisted. I removed the case and looked over the board, but nothing looked visibly damaged. All the pins on the connectors appear fine and the cartridges fit snugly, but aren't too tight.

This motherboard hasn't gotten a ton of use, since my other board is set up for netbooting. However, it never had any problems before this. It went unused for at least six months before I first encountered the lock ups.

I appreciate any help or advice you can share with me.

[landisama]

Check the fans. I had a similar problem with a Naomi 1 with a defective fan. The board reached the overheat temperature and stopped working.

[Spectre]

Fans not spinning is a common issue and the gpu can get fried very quickly, means dead mobo and not economical to repair afaik

[richmal]

Check the fans. I had a similar problem with a Naomi 1 with a defective fan. The board reached the overheat temperature and stopped working.

^^^^^^ This

[doop9174]

Thanks for all the great replies. I'll get some replacement fans and hopefully get this working again.