Build goes from fine to won't post to fine to won't post

[naddicott]

All components listed in first post of this thread. (Vid card upgraded to RX480)

The system has been doing fine. Then one day I power it up and it never gets to the BIOS. CPU light on the Motherboard is lit red.

First thing I tried was swapping out the PSU with a new 1000W model, same series. No luck. I figure the problem either lies with the motherboard or the CPU. Rather than continue to buy components for guesswork, I take it into a nearby shop for their "diagnostic" service.

At the shop, they reproduce the issue. Try single RAM, resetting CMOS. No love. Check it into the queue for full diagnostic. Six days later, I drop in in person to see if there's any update and they take a look at it then - boots fine repeatedly, unable to reproduce my issue. They refund my deposit and I bring my system home.

At home, back to no post with red CPU light on the motherboard. I clear CMOS again. I re-do power connections, remove VGA card, go to 1 RAM module, remove heatsink, apply new thermal paste and re-seat the CPU and heat sink. I lay the system on its side. Every time, same thing. All the fans turn on, and the red CPU light shines.

Given I saw the whole system working fine (again) a few hours ago, I now suspect the CPU is OK and that the motherboard needs replacing.

Any advice is welcome.

 

[Ketchup]

What are the power connections outside of the computer like (battery backup, power strip, etc). What all do you have plugged into the device when you are trying to get it to boot (USB, video card, etc)?

The idea here is you want to ensure a good power source and remove any items that aren't absolutely necessary for boot, to see if you can get to a base point where it will boot.

 

[naddicott]

Surge protector power strip with just the system and a monitor plugged in. Graphics card is out, PCI-e wireless adapter is out. Only thing in USB is keyboard. One stick of RAM.

Power on, all fans turn on. Red "CPU" light on steady. No post, no signal to the monitor.

Tried with monitor and keyboard unplugged too... same red light.

 

[Ketchup]

Unplug computer. Hit power button to discharge PSU. Plug computer directly into wall (you may also want to do a CMOS reset). Power on again. If that doesn't work, try another outlet/room.

 

[naddicott]

Done. Direct to wall in office / Hallway / Living room. (Reset CMOS back in office) Same.

I have an unopened Z270 Motherboard from a nearby shop. Is that a reasonable next step? I also picked up a 900W UPS because I do think funkiness with power / electric was part of the story here.

 

[Ketchup]

Wow. Sounds like something is dying. I think the repair shop got lucky. You could try another board.

Are fans spinning? I have seen where a short from the case can cause pretty much nothing to start when the button is hit.

 

[naddicott]

All fans spin fine. Here goes new MB...

 

[naddicott]

Installing windows - the ASUS Motherboard noticed the CPU fan was not reporting its speed, but I can tell it's on, so I told it to ignore. Upside of all this is I didn't want to lose data on the old SSD so now I have a Samsung 960 EVO M.2 drive.

I guess I'll order a replacement fan...

 

[RolandJS]

+1 on the UPS! I have a few around the apartment to protect computer center and expensive VHS/DVD & TV combinations.

 

[DAPUNISHER]

The UPS is a good idea regardless; make certain it is AVR as they are the best. FYI: I have seen usb transmitters cause boot issues. Last time it happened to a system I worked on, it was a bluetooth transmitter. Remove the keyboard's transmitter next time it happens. It did not completely fail to boot though, just throw up error code 92 after prolonged period of waiting for a monitor signal.

 

[viknesh]

All components listed in first post of this thread. (Vid card upgraded to RX480)

The system has been doing fine. Then one day I power it up and it never gets to the BIOS. CPU light on the Motherboard is lit red.

First thing I tried was swapping out the PSU with a new 1000W model, same series. No luck. I figure the problem either lies with the motherboard or the CPU. Rather than continue to buy components for guesswork, I take it into a nearby shop for their "diagnostic" service.

At the shop, they reproduce the issue. Try single RAM, resetting CMOS. No love. Check it into the queue for full diagnostic. Six days later, I drop in in person to see if there's any update and they take a look at it then - boots fine repeatedly, unable to reproduce my issue. They refund my deposit and I bring my system home.

At home, back to no post with red CPU light on the motherboard. I clear CMOS again. I re-do power connections, remove VGA card, go to 1 RAM module, remove heatsink, apply new thermal paste and re-seat the CPU and heat sink. I lay the system on its side. Every time, same thing. All the fans turn on, and the red CPU light shines.

Given I saw the whole system working fine (again) a few hours ago, I now suspect the CPU is OK and that the motherboard needs replacing.

Any advice is welcome.

I have this exact same problem now, but few more issues. Posted in a new thread. Replacing motherboard is the only way?