Laptop fans seem to intermittently not work, overheating while gaming

[SpaceCore]

Laptop is Acer vn7-571g. It seems the past couple days that the back exhaust fans stop working while gaming sometimes. I've played a game a few times for 10-20 min, have felt the fans putting out warm air and continue to work fine for long periods of time, temps remain ok. But after an hour or two I'll experience framerate drops, notice my temps are upper 90s and when I go to feel for exhaust, barely any air is moving. One time the laptop actually shut itself down. Any time I notice this happening and restart myself, once booted the fans run fine and I can feel air movement again for the next couple min as it works to reduce temps, and will work again for a while next time a game runs.

It's odd as this started happening once my house got colder for the fall which I would think would help reduce the temps (coincidence?). Almost makes me think it's a temp sensor issue or a software/driver/bios issue, but there is one other thing that may be related?

This one has been going on for a while now. When gaming and things warm up (75-85Cish), I hear a staticky/buzzing sound that slowly ramps up to a certain volume coming from the front left side of the laptop where the left speaker is. When I quit the game and temps drop after a minute or two the sound gets progressively fainter till disappearing. I was planning to open it up soon anyway to repaste and clean thinking lowering the temps a few C would fix it, was considering just taking out the left speaker if not.

 

[webworkings]

Sounds like you already have in hand what you should do. First try cleaning and repasting. If that doesn't resolve it, you may need to replace the fan.

 

[SpaceCore]

Update. I never had any luck getting programs like speedfan to recognize my laptop's fans, however I found a thread where someone figured out how to force the fans on in Acer Nitro laptops using RWeverything to change the embedded controller values. I tried setting them to manual 100% speed and indeed it works. I've never heard them get to 100% on their own. Did this and played a game for many hours, highest my temps went to was ~75 C. I still intend to open up the laptop to repaste and clean, but for now I made .bat files to switch between auto and full speed when gaming. This makes me think again that it isn't the fans going bad, but some kind of bios/driver/sensor issue where they aren't properly triggering?

 

[webworkings]

Depends on what temps they were set to turn on at. Every device is different. If you can get it to set it to 100% perhaps you can get it to change the turn on temp? That is what speedfan is good for, but as you stated it hasn't worked for you.