PC Freezes, full red CPU LED occasionally, and more!

Aug 8, 2018
Best answers
tl;dr Red cpu led sometimes, wont boot up to GPU sometimes, PC completely freezes.

I've got a plethora of issues with my PC and I'm not sure where I'm going wrong.

I have done a lot of diagnostics, and I am no closer to finding an/ the issue.

I've had a very good look at it and noticed three issues that I feel need an explanation, before I just start replacing everything when some parts worked perfectly fine. All the issues I've had have been tested and are reproduceable while bread boarding.

1. Occasionally, it won't turn on at all, and I mean, at all. The CPU LED is on and fully red. This is out of the blue, I'll restart the PC that booted perfectly find moments ago, and it's just full red LED. I checked if it had overheated, CPU was cold as a stone. Just in case, took the CPU out, reapplied the thermal paste and stuck it back in, still didn't work.
The thing that baffles me on this one is that I can leave it for a day, come back to it and it turns on perfectly fine.

2. While it's booting, I'll watch the LEDs flash, I assume they indicate the part being checked is there and functional. I'll watch the sequence of lights flash CPU, Memory, CPU, Memory, GPU... oh wait, GPU didn't flash. And it won't boot. The GPU light will not turn on and POST stops there. This fixed its self after I reseated everything, I doubt it's the GPU as I reseated the GPU multiple times but that didn't fix it. Just worried this one might come back to bite me in the ass as it was happening frequently.

3. It will freeze after various timespans, but roughly I probably get 10 minutes out of it if I'm lucky. It has froze on the login screen, it has froze mid video. By freeze, I mean everything stops including sound, and stays like that until I reboot. It hasn't frozen in bios no matter how long I leave it. This screams an issue with the Hard Drive, as I've checked every single stick of Ram in every Ram slot and no matter what it makes no difference. However recently it did something with the hard drive while I was booting it, I can't quite remember what it was however, but after it finished and loaded OS, it still froze.

I have performed a lot of diagnostics, you name it, I've probably done it, but I'm happy to do any tests again in hope that my PC can be revived to it's former glory (really I'm too poor to replace the whole thing). Unfortunately, I have no other PC I can use to test parts in which would be invaluable, but I'm hoping the wise people here can give me some outs. The issue being I could swear some issues are related, like it freezes, then I'll reboot, and get the red CPU LED of death and be like 'What happened there? Maybe it's not the hard drive'.

I don't currently have my specs to hand, however I'll list what I can remember. I'll update the post later with more detail if there wasn't enough already.

Processor - AMD FX 8350
RAM - 12 GB
Hard Drive - 2 TB HDD Seagate
Graphics Card - GTX 1060
Motherboard - ASUS AMD AM3+ 990X EVO R2.0
PSU - Can't remember the specifics, but could swear it can take between 100 and 750 watts
Operating System - Windows 7

I'm young and inexperienced when it comes to this stuff, any advice would be greatly appreciated, if you organise your posts by putting 1, 2 and 3 before the issue you wish to discuss, it'll be a lot more organised for everyone.

Thanks for your help all!


May 17, 2017
Best answers
Sounds like it's either your motherboard or your PSU. PSU is the easiest to try to check/replace. First, how old is this system? You're going to need to open the computer up (unplug it from the wall and hold the power button for 10 seconds or so to burn any residual electricity) and find SOMETHING about the power supply. Brand name and wattage would be great. If it's modular, that would be great to know as well. Let me know.