Question Coil whine noise and power switching issues during rendering

[Cendoohh]

Hi everyone,
I’m reaching out to see if anyone has experienced a similar issue or has any suggestions.

Custom-built laptop with Windows 11
CPU AMD Ryzen 9 5900HX
Power mode set to dGPU only in BIOS (mobile RTX 3080 16gb 150+15w)
Inference workloads via Python-based AI rendering (e.g. ComfyUI/Stable Diffusion/Framepack)
Rndering through Premiere Pro
I'm dealing with a couple of issues on my laptop that I can't seem to fully figure out, and I'm hoping someone here might have some insights or similar experience.

Over the past few days, I've noticed that the coil whine coming from the laptop has become noticeably louder, especially when launching heavy GPU tasks like AI rendering (sometimes it makes noise even when moving the mouse while doing notihng. When I stop the mouse, it gets completely silent). It used to be a soft, barely audible noise, but now it's more like a sharp buzzing or whistling, and it's much more frequent.

At the same time, something more concerning has started happening: during these rendering tasks, the system randomly seems to switch from AC power to battery for just a brief moment, then switches back. I can tell because the keyboard backlight dims momentarily (as it normally does when unplugging the charger), and I’ve confirmed it through the Windows Event Viewer (there are entries saying “Power source changed” even though the charger is firmly connected and hasn’t moved (of course I can see that aswell on the icontray and I've tested it with HWInfo aswell. It doesn't happen when I'm just browsing or in idle.


I’ve done quite a bit of testing already. I reinstalled the NVIDIA drivers with a clean install, switched the BIOS setting from dGPU only to hybrid graphics and then back to dGPU because nothing changed, and even adjusted my Windows power plan to limit the CPU performance to 85%. That last step helped reduce CPU temps from 95°C (while rendering) to about 83°C during rendering, but the power-switching issue still happens, albeit maybe a little less frequently.


So far, the AC adapter seems to work fine under light load, and I don’t notice any looseness in the power jack. But during inference and rendering, especially when the GPU is working hard, something triggers these quick drops (I'm not sure about what I'm about to say, but that seems to happen especially when I START the rendering. For example, if I'm in Premier Pro and I press to "Export", the power supply problem happens and then it goes back to normal. When I do inference with, for example Framepack, it takes 25 steps for every second of video generated...well, everytime it finished those 25 steps and it gets ready for the next 25 steps, this happens...I repeat I'm not really sure about this, I will have to test some more)

The laptop is 4 years old and 2 years ago It started having problems on performance so I sentit back and they said that the 3080 "couldn't stay active" because a MOSFET was broken. So they changed the MOSFET with a new one and they tested it for days and changed some more things to make it like new. Indeed everything was perfect and the performances were great. Now they are great aswell, but these problems+the heating of the CPU make me think something is about to die.

I’d really appreciate any ideas, especially if someone has experienced something similar.


Thanks in advance for any advice.

Spoiler: Event Viewer

 

[helpstar]

does it happen while using only battery as well?
check with adifferent ac adapter
check the ac connection on the latop, after time and usage solder joints can break.

while the gpu had problems before, the problem could be back again.

 

[Cendoohh]

does it happen while using only battery as well?
check with adifferent ac adapter
check the ac connection on the latop, after time and usage solder joints can break.

while the gpu had problems before, the problem could be back again.

Unfortunately I don't have another as of now. I'm in the middle of nowhere in Australia, I will probably not be able to try a different one for 6 months or so. But, wouldn't it be weird if it was the adapter and it happens only when rendering or during inference?
What do you mean by "only battery"?
I tried to check the connection but everything looks fine. Indeed while using the laptop normally (no rendering), everything looks fine (except for the coil whine being worse than before).
Yes, the GPU had problems, but apparently the problem wasn't in the GPU, but in a mosfet that broke and they changed it to a new one. Maybe even the new one broke again?

ps: I noticed via HWInfo that while rendering the CPU start throttling going up to 95/96°. I tried to reduce its maximum usage to 80% and the temperature while rendering is now at 73/75°. I'll have to see if the battery problem still persist. The coil whine didn't change, still loud

 

[helpstar]

What do you mean by "only battery"?

Disconnect the ac adapter and run the laptop

Yes, the GPU had problems, but apparently the problem wasn't in the GPU, but in a mosfet that broke and they changed it to a new one. Maybe even the new one broke again?

maybe the problem why the mosfet blew up was not resolved and only the symptom, or a different mosfet is going to get faulty
could be a power problem inside the laptop

which laptop brand and exact model is it?

 

[Cendoohh]

Disconnect the ac adapter and run the laptop

If I do that, how can I have the problem of the power switching from the ac o battery only? If I disconnect the ac I will just have battery only and that's it, no? What else could happen?
As for the coil whine, the noise seems to be the same even in battery only

maybe the problem why the mosfet blew up was not resolved and only the symptom, or a different mosfet is going to get faulty
could be a power problem inside the laptop

which laptop brand and exact model is it?

It's a custom-built laptop. Barebone and motherboard are made by TongFang

 

[helpstar]

As for the coil whine, the noise seems to be the same even in battery only

That´s what I was thinking of, it´s clearly a component inside the laptop

if possible let repair or replace the motherboard

 

[Cendoohh]

That´s what I was thinking of, it´s clearly a component inside the laptop

if possible let repair or replace the motherboard

The warranty was for 3 years, it expired 1 year ago...damn...
It sounds like a bad situation? Like it could die at any moment?

Edit:
Update: I tried to disconnect the AC and use battery only and reboot the pc so it would start directly with battery only. The laptop is completely silent. As soon as I connect the AC, it starts to be really noisy.

 

[Cendoohh]

Another update: I started a render test with GPU-Z and the coil whine goes crazy while doing that, so it should be the GPU. Maybe the VRMs