Question CPU Overheating at POST & BIOS

[Itsrapiddave2]

So my dad recently bought a motherboard, CPU and AIO cooler from eBay and there's a fair few issues to start with. Before I get into that, here are the system specs:

MB: ASUS X99-A
CPU: Intel i7-5820k
RAM: 4x4GB Crucial DDR4

So, upon starting the system, sometimes I'm greeted with an error stating the BIOS settings need to be recovered, I've reset to default, reset the CMOS and replaced the battery, but that still appears. When I load into the BIOS, everything seems fine except my CPU temperature rockets from 40°C all the way to 80°C in like 10 seconds.

At first, I thought it was the AIO cooler that came with the MB and CPU, as I could hear bubbling and thought air had gotten trapped and wouldn't cool the CPU properly. I've now replaced the AIO cooler with a dual radiator one, there's no bubbling but the CPU still reaches super high temps with seemingly no difference from the previous cooler.

I've contacted the seller and they're saying there's no way it's the CPU as they said everything worked fine before they sent it.

Thermal paste is 100% applied properly (I used to work for a computer repair shop so I reapplied thermal paste often).

I've bought another CPU to test if it's the CPU that is faulty and will then try and get a refund, but then there's still the issue of the BIOS settings seemingly needing to be recovered!

Does anybody have any idea on what could be making the CPU so hot? Or what might be wrong with the BIOS? As looking online only goes over the basics like reapplying thermal paste and things like that. Any help is really appreciated!

Also, the MB doesn't give any useful Q Codes on the LED panel.

EDIT: I've since tried another i7-5820k on the system, which was at 50°C for around a minute, before shooting up to 99°C. So I think the motherboard may be the issue.

 

[Ralston18]

PSU: make, model, wattage, age, condition (original, new, refurbished, used)?

History of heavy use for gaming, video editing, or mining?

 

[Itsrapiddave2]

PSU: make, model, wattage, age, condition (original, new, refurbished, used)?

History of heavy use for gaming, video editing, or mining?

It is a Cooler Master v750 750w PSU

It seems to be in good condition and was working perfectly fine in a previous build a few days ago.

There's almost no heavy use against it, my dad uses it for torrenting files and general daily PC use. I can't be certain on its age but I think it's only around a year old.

And believe me, I'm well aware that the specs for the PC are far beyond what is needed for that usage, but he doesn't listen and always goes for higher end stuff than he needs.

 

[Ralston18]

Take a look at the following link:

Best Power Supplies of 2022 - Top PSUs for Gaming PCs | Tom's Hardware (tomshardware.com)

Not with the immediate intent that a new PSU needs to be purchased.

Just work through 2 or 3 of the calculators to determine if the PSU is indeed capable of supporting the host system. I would expect so but a closer look is recommended. If any given component has a range of wattage values then use the high end value. For GPUs, I prefer to use the recommended PSU size. There are differing viewpoints about that....

= = = =

Also: "Also, the MB doesn't give any useful Q Codes on the LED panel. "

What codes are provided?

 

[DRagor]

There is a possibility of motherboard issue - the kind of 'it works except when it doesn't'. There are two ways motherboard could cause CPU overheat. One is false readings - you would need another mobo to test that though. Second is applying too high voltage to CPU. I'm assuming BIOS settings are voltage on auto? In that case check what is actual voltage applied to CPU, and/or change to from auto to manual and see if temp change with different voltage.

 

[Itsrapiddave2]

Take a look at the following link:

Best Power Supplies of 2022 - Top PSUs for Gaming PCs | Tom's Hardware (tomshardware.com)

Not with the immediate intent that a new PSU needs to be purchased.

Just work through 2 or 3 of the calculators to determine if the PSU is indeed capable of supporting the host system. I would expect so but a closer look is recommended. If any given component has a range of wattage values then use the high end value. For GPUs, I prefer to use the recommended PSU size. There are differing viewpoints about that....

= = = =

Also: "Also, the MB doesn't give any useful Q Codes on the LED panel. "

What codes are provided?

I'd rather not purchase another PSU if I can help it, so I'll have to keep that as a last resort, especially since I have another system the PSU works with.

The only Q Codes that come up are '99' in POST, which is "Super IO initialisation" and when I enter the BIOS, 'CE' which just states that I am in the BIOS.

I've tested it with another i7-5820k today, at first it stayed around 50°C in BIOS for a while, so I went through the BIOS to look around, only to find it reached 99°C, so I quickly turned the machine off.

I'm now starting to believe that the motherboard may be the issue, as this was 2nd hand from eBay.

 

[Ralston18]

Compare the wattage demands of the system where the PSU was working fine to the wattage demands of the PSU's current host computer.

What are wattages?

And do remember that PSU's provide different voltages (3, 5, and 12) to varying system components on different voltage rails.

If the PSU is unable to keep up with the power requirements on any rail or unable to respond quickly enough to some sudden peak demand then there will be all sorts of problems.

It could well be that the motherboard is the problem: however, probably worth some additional effort eliminate the PSU as a potential suspect.

Do you have a multi-meter and know how to use it? Or know someone who does?

FYI:

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Not a full test because the PSU is not under load. However, any voltages out of tolerance would be an indication of things going wrong.

All in all it will be a matter of elimination .