CPU light is on indicating failure but PC works

[Zalosath]

Hi,

 

I'm working on a PC right now and I've got an issue with the CPU debug light being constantly on. 

 

The PC will turn on normally (but will still have the CPU debug light on), I ran a Cinebench test and all looked good. 

 

The important part though: More often than not the PC will not boot, the fans spin and the CPU light is on, to get it to boot again I have to reflash the BIOS.

 

I've updated the BIOS to support 5000 series.

 

MBD: B450 Tomahawk Max II

CPU: Ryzen 7 5800x

Cooler: NZXT KRAKEN X53

GPU: GTX 970

RAM: Corsair LPX ~2666MHz

 

The PC recently stopped working, so I upgraded the motherboard from a B450 DS3H to a B450 Tomahawk Max II, still wasn't working so tried the CPU in my machine and viola, CPU is broken. So I upgraded that too from a 2700 to a 5800x. 

 

Not sure what's causing this, any ideas?

 

UPDATE: BIOS only needs reflashing if I unplug and replug the power cable.

 

[TeamBeasted]

When it does boot correctly, have you made sure to get the latest chipset drivers, etc?

[IkeaGnome]

8 hours ago, Zalosath said:

UPDATE: BIOS only needs reflashing if I unplug and replug the power cable.

Just for shits and giggles, try a new CMOS battery. CR2032 if you have one laying around. If either of those motherboards are old, there's a chance it's dead. When BIOS does weird stuff that's usually what I look at first. 

[Zalosath]

12 hours ago, TeamBeasted said:

When it does boot correctly, have you made sure to get the latest chipset drivers, etc?

Yeah updated to latest for the board. Only boots correctly when I reflash the BIOS. But I'll only have to reflash it if the power cable is unplugged.

 

12 hours ago, IkeaGnome said:

Just for shits and giggles, try a new CMOS battery. CR2032 if you have one laying around. If either of those motherboards are old, there's a chance it's dead. When BIOS does weird stuff that's usually what I look at first. 

Probably worth a try, though the Tomahawk II is new from Amazon.

[Beerzerker]

12 minutes ago, Zalosath said:

Yeah updated to latest for the board. Only boots correctly when I reflash the BIOS. But I'll only have to reflash it if the power cable is unplugged.

 

Probably worth a try, though the Tomahawk II is new from Amazon.

Seriously, that don't mean shit because a battery can get weak or die just from sitting on the shelf and it's the same with it sitting in a board ..... On a shelf in the warehouse.

If you have a voltmeter, you can see where the voltage is for the battery and if it's at or below 2.9v's, replace and be done with it.
Normally a new 2032 or any like it has 3.0v's when new, some a touch more and as long as your battery is at or close to 3.0v it's fine.

[TeamBeasted]

2 hours ago, Zalosath said:

Yeah updated to latest for the board. Only boots correctly when I reflash the BIOS. But I'll only have to reflash it if the power cable is unplugged.

 

Probably worth a try, though the Tomahawk II is new from Amazon.

There's a chance the board is faulty right from the production floor. Could always RMA it. 

[Zalosath]

On 11/28/2021 at 3:13 PM, TeamBeasted said:

There's a chance the board is faulty right from the production floor. Could always RMA it. 

I RMAd it in the end. The new board has the same issue replaced the CPU and Mobo and still just the same issue. CPU light is on indicating failure but works just fine after a BIOS update. BIOS update needed every time you unplug or update the system or BIOS. 

[Zalosath]

Seems silly but after a ridiculous amount of time spent debugging, it's the case.

 

I pulled the MB out of the case to test the individual components and was surprised when the PC booted with no issues.

 

My best guess is a short with a standoff but honestly I have no idea. The standoffs all look clean and the MB has no obvious burns or other symptoms of a short. I've ordered a new case and this H510 is going to the tip after years of terrible PC case-ness. 

 

Posting in-case someone has similar symptoms and couldn't figure out why.

 

EDIT: Case was not the problem after all. Failing graphics card is. The PC will start fine when display port is not plugged in but refuses to boot when it is. Ordered a new GPU and fingers crossed it's the solution, only after upgrading literally every other component *facepalm*