Question PC crashed while gaming. Turns on but won't POST & there's a white CPU LED on motherboard ?

[Epicdan22]

I've had a pc that was built a year and a half ago. Yesterday morning in the middle of gaming the game hard froze. Sound kept going but could ctrl+alt+del or anything. Had to use the power button to turn off pc. Turned it back on and the cpu light on the mobo is on. Tested connections,reseated the cpu. Put the gpu in another pc and that gpu came on in the other pc fine. Tested each ram stick separately in all four slots. Pulled the gpu from the old pc and put it in the current one and same issue. No post. No lights on the gpu either. All fans running like normally. Lights on the case,ram and radiator all working and running at the speed I'm used. Can't figure out which is it. Any help?

Specs on the build

CPU-AMD Ryzen 9 5900x

GPU-NVIDIA RTX 3080

Cooler-NZXT Kraken x63 Cooler

Case-NZXT H510 Flow Case

Mobo- MSI B550-A PRO

Ram - Team T-Force Delta RRB 16 GB Ram 3200MHZ

SSD-Western Digital 1TB NVME

PSU-EVGA SuperNOVA 850W GA Gold

 

[Misgar]

When you "Tested each stick separately in all four slots" what were the results?

Pass or Fail?

Were you testing the RAM in the spare computer or in the rig with the fault?

What RAM test did you run?

1). System boots to BIOS.
2). MemTest86
3). Something else

Was the RAM overclocked with DOCP. You cannot expect 4 sticks of RAM to run at the XMP settings which work fine with only 2 sticks fitted.

Do you have 4x16GB (64GB RAM) or 4x4GB (16GB RAM)

 

[Epicdan22]

Tested each stick in all four slots and all failed, no changes. Still the white cpu light lit up.
Testing ram in the rig with the fault. I took a 2080 from the spare computer and put it in the fault one and it also didn't light up. The 3080 in the spare computer booted up fine.
I should mention I picked up a different motherboard last night(Another msi b550) and in that mobo I got the same thing with the cpu debug light on instantly.
I had 2x8gb ram in there. I then swapped out a working set of 2x16gb in there and got the same result. At the time of the crash they were set to 3200 and I believe had the xmp profile to run at their listed speed.

 

[NanoSuit3]

This actually happened to me before but it was a stupid reason. Dust build up, not enough power and needed firmware updates. Could be just me though but consider anything possible

 

[Epicdan22]

This actually happened to me before but it was a stupid reason. Dust build up, not enough power and needed firmware updates. Could be just me though but consider anything possible

surely it can't just be dust buildup right? I've cleaned out the case now since I took apart and rebuilt it twice now. Would trying a different power supply be best? Everything boots up and lights up except for my FE gpu. Even though the fans are on.

 

[Epicdan22]

When you "Tested each stick separately in all four slots" what were the results?

Pass or Fail?

Were you testing the RAM in the spare computer or in the rig with the fault?

What RAM test did you run?

1). System boots to BIOS.
2). MemTest86
3). Something else

Was the RAM overclocked with DOCP. You cannot expect 4 sticks of RAM to run at the XMP settings which work fine with only 2 sticks fitted.

Do you have 4x16GB (64GB RAM) or 4x4GB (16GB RAM)

2x8gb. Can't get into bios because it doesnt post. No oc on the ram besides xmp i guess to make it run at 3200

 

[Misgar]

Sorry, I'm still confused. Have you tested the RAM in another working system?

Have you tried the fitting just two sticks of RAM and running without XMP, i.e. at 2133 or 2400MHz?

 

[Epicdan22]

Sorry, I'm still confused. Have you tested the RAM in another working system?

Have you tried the fitting just two sticks of RAM and running without XMP, i.e. at 2133 or 2400MHz?

I tried the ram in another pc. They worked. Tried a brand new set of ram sticks and they worked too. In the faulty pc I get the same boot situation. Everything on but a white debug light on cpu. My gpu is on but no lights are on. However in another pc it works fine. I can't get into the bios to change the speeds or turn off XMP because it wont post. All of the ram sticks I've used have just been sets of two. 2x8gb(16gb) and then the new set 2x16(32gb)

 

[Misgar]

Have you tried booting with no RAM fitted. Sometimes this wakes things up. When it complains with several beeps, shut down and fit one or two DIMMs.

 

[Epicdan22]

Yeah I tried that as well. What ended up working for me was swapping out the Ryzen cpu. Picked up a 5800x3d. It booted right up. I suppose it was the cpu after all. Dont know how though. Curious if things would work if I put the other cpu back in or just let it be now.

 

[Misgar]

Do you feel lucky putting a suspect CPU back in a working system? Only you can decide if it's worth the risk.