CPU over heating errors

[Bondi00711]

System gives overheating errors of CPU and Motherboard even though core temp shows CPU stress test shows running temperature of 76 degrees. Error probably comes rom core temp showing 93 degrees maximum on average

[Bill_To]

Greetings @Bondi00711 

Is your PC shutting down or acting unstable?

Is your PC in warranty?

93 Degree Celsius: CPU or other MB temps could be considered somewhat toasty. Other MB component temps or discrete (if applicable) GPU temps may be close to the red zone.

HWiNFO portable (free) can provide a detailed view of component temps and various fan speeds. Run HWiNFO portable using sensors only.

First, try cleaning external vents using compressed air. It is best to avoid using canned compressed air if possible. Canned compressed air generates moisture. Don't start the PC for a while (let it dry) if you do use canned compressed air.

I use standard AC electrical outlet dust busters (or cordless battery powered) dust busters instead of canned air.

Your second option would be to disassemble the PC.

Clean the: MB, fans, and ducts using compressed air. Maybe clean and redo: the CPU TIM and GPU TIM if required.

I don't think a limited one year warranty would cover routine internal cleaning/maintenance.

But a local PC Tech would probably clean your PC's internals and reapply TIM (if indicated) at a standard hourly rate if your PC is not in warranty.

Regards

[Bondi00711]

Thank you Bill_To for your valuable input.

I have d/l the HWINFO and found it to be a  very interesting piece of software. It has shown that in running 2 consecutive runs of the CPU stress test, the temperature got up to 88 degrees and did trip off the alarm once. The average temp at idle sits around 60 degrees

Following my complaint to HP, they advised me to change the power setting to "Best Power Efficiency", which has reduced the frequency of the error notice, but my concern is that I have had errors when issuing a new command at idle.

I do not expect to get errors like this with a brand new computer when all I have done so far is to load my application software and I have not started to use it yet.

I appreciate your input and if you have any further ideas, please let me know.

[Bill_To]

Greetings @Bondi00711 

My pleasure.

Is your PC stable when you stress test the processor?

Newer Intel/AMD CPUs are designed to run hotter for long periods of time.

Since your PC is brand new cleaning the internals would, most likely, not solve the temp problem.

Use the PC for a while to see how it goes.

You would have to talk to HP Support if you have any PC performance issues (shutdowns/restarts or freezing) during the warranty period.

Regards

[mark9210]

The mismatch you're seeing is common and usually comes down to which sensor is reporting, not a measurement error.

Why Core Temp and the system's overheating alert disagree:

- Core Temp reads the CPU's own digital thermal sensor (DTS), reporting per-core temps during your stress test.
- HP's overheating alerts (BIOS/embedded controller) often pull from separate sensors — motherboard/VRM/chipset thermal zones — not just the CPU package. In a slim all-in-one like the OmniStudio 27, these board-level sensors sit close to the PSU and VRM circuitry, which run hotter than the CPU itself in a cramped chassis.
- The embedded controller (EC) also samples much faster than most monitoring software polls, so it can catch brief spikes that Core Temp's rolling average/max never registers.

So a 76°C CPU reading alongside a "CPU/motherboard overheating" error usually means: the CPU itself is fine, but a nearby sensor (motherboard, VRM, or the EC's own trip point) is what's actually triggering the alert — not Core Temp's number.

What to check next:

1. Run HWiNFO64 instead of/alongside Core Temp — it exposes motherboard, VRM, and chipset sensors that Core Temp doesn't show, so you can see which sensor is actually near its limit.

2. Check HP's BIOS/diagnostics tool (HP PC Hardware Diagnostics) — it reads the same sensors HP's error system uses, so it'll usually name the specific zone (CPU vs. board) that's tripping.

3. Airflow/dust — AIOs like this rely on a single rear vent path; dust buildup or a wall-mount/enclosed placement blocking rear vents is a very common trigger for board-level (not CPU) thermal errors on this form factor.

4. Update BIOS — HP has previously issued BIOS updates that adjust thermal thresholds/false-trip sensor readings on AIO models; worth checking Support Assistant for a newer BIOS specifically for the 27-cu0000.

5. If reseating/cleaning doesn't help and HWiNFO shows a specific sensor pegged near its limit even at idle, that points to a failing thermal sensor or VRM issue — warranty repair territory rather than a software fix.