No POST after reboot

pholgersson · July 26, 2020

Hi!

I have an issue that I'm not able to figure out how to solve.

When I cold start my computer everything is normal, even if I reboot the computer shortly after a cold start it's fine.

But if I've used it for a while and then reboot I get no post, nothing happens; monitors are black and neither mouse or keyboard is turned on.

I don't know if this is related, but sometimes when I play a game my monitors go black and after a couple of seconds the computer reboots (I think) into the same issue.

I cannot find the solution in any forum, the closest one is this:

Even if I haven't seen any other issues regarding faulty CMOS battery, after reading this post I put in a new one.

At first I thought this fixed the issue since the computer seemed to be working correctly, but after approx 1 week I noticed that the same issue was still there.

Both the old and the new batteries are CR2032 3volt Lithium, but not the same brand.

Is it possible that a new CMOS battery will fix my issues and that the one I put in is somehow not compatible?

If the CMOS battery is not the solution, please help me find what it is, any inputs are appreciated!

Specs:
MOBO: Asus TUF B450m-PLUS Gaming with BIOS version 2202 (latest)

OS: Win 10 64

PSU: Corsair RM850x

GPU: ASUS GeForce GTX 970 STRIX 4GB DirectCU II OC

CPU: Ryzen 7 3700X (Asus optimal setting in BIOS otherwise NOT OC)

RAM: Corsair Vengeance LPX Black 16GB (2x8) 3200 MHz CL16 (DOCP enabled to get 3200MHz)

COOLER: Noctua NH-U12S chromax.black

DRIVE: Samsung 970 evo plus M.2 500GB

CASE: Fractal Design Node 804

Temps when manual reboot: CPU: 55-60, GPU: approx 60 (Celsius)

Temps when gaming: Both CPU and GPU approx 70 (Celsius)

Chris Pratt · July 26, 2020

I'd turn off the ASUS Optimal setting. Reset the BIOS to factory defaults, re-enable XMP, and then try that for a while. If you still have issues, it could be a faulty power supply.

pholgersson · July 27, 2020

4 hours ago, Chris Pratt said:

I'd turn off the ASUS Optimal setting. Reset the BIOS to factory defaults, re-enable XMP, and then try that for a while. If you still have issues, it could be a faulty power supply.

Thanks for the tip, but wont that remove the B450's support for Ryzen 3000? (I had to update BIOS before putting this cpu in, was running a 2400G before)

Just out of interest, what make you believe it is the PSU that is faulty? Any particular reason?

I also want to add that I got the same problem when I after 4 hours of gaming without any issues shutdown the computer and turned it back on manually after about 15 seconds.