Red cpu light issue

kallope · 6 Jun 2026 at 17:04

Afternoon all,

This week I was playing a game and then my screens all went black and the lights on my fans all turned off however continued to run. I held the power button for a while and this didn’t turn the computer off.

When I looked inside, the debug light for cpu is red.

I have a Ryzan 7800x3d and a gigabyte b650 gaming x ax motherboard. Power supply is Corsair rm1000x. Have also tried a Corsair’s rm 850.

I have removed the cooler and cpu and reseated both, removed the ram and reseated it, tried each stick one at a time, removed the graphic cards and all peripheries, removed the battery and joined the cmos clear pins and tried a new power supply.

After all this, the cpu light is still red, the computer doesn’t boot and lights on the fans and ram do no light up.

I’m run out of ideas on how to fix the issue, so looking for any further advise from you guys.

I fear either the motherboard or cpu may have given up on me.

Thanks for any advise in advance.

tamzzy · 6 Jun 2026 at 17:06

dead cpu most likely, time for RMA

obvs the only way to test is to swap the CPU out, as you can't even post

kallope · 7 Jun 2026 at 20:24

tamzzy said:
dead cpu most likely, time for RMA

obvs the only way to test is to swap the CPU out, as you can't even post

Thanks for the help,

I did feel it might be the cpu. Will see if I can take it a local IT repairs shop to see if they have a system that it can be tested in.

Thanks again.

jigger · 13 Jun 2026 at 12:47

Could be anything really. Most likely suspects are Mobo, CPU or RAM.

adrichardson81 · 15 Jun 2026 at 10:32

If the debug lights are on, I'd be looking at the CPU rather than the motherboard. If you've tested each ram stick separately in different slots, you can rule provisionally rule them out (you might have lost both sticks at the same time, though that's unlikely). Likewise GPU and PSU are unlikely to be the culprits.
If you can drop it in a test system, that should answer your question. I don't suppose you heard a pop just before it died? If you look at the underside of the CPU, is there any bulging?