An hour or so ago my laptop (Acer Aspire V Nitro) started making this very disconcerting noise, as if my fan kept hitting something. This had happened before, and usually I restarted my pc and somehow the noise didn't appear again on start-up. However this time I didn't restart it, and after a while sounded like it hit something and that fan stopped working. Only my right one is working now I'm pretty sure.
Not only that, but right at the moment the fan stopped working my processor started to run very slowly, at 0.78 GHz (I was gaming atm, hence why I noticed it). It now stays at that speed no matter what.
I plan to clean the dust from my fans in a bit, and see if that changes anything, but I figured I would ask here asap and see if you guys have any idea of what this may be (truly just a fan issue, or something more serious?).
Thanks in advance
EDIT: So I just cleaned it and started up my laptop, and I noticed that at first the processor was working at a perfectly fine high speed. However, after a while, it once again settled down to 0,78 GHz. This makes me think there's nothing wrong with the processor (what a relief) but I'd still like to know a solution
Summarizing, you had a failing blower that finally failed completely. The usual cause is bearing failure - and the noise you describe is typical of this problem. This blower is crucial to the processor cooling and, without it working, the processor is overheating and (eventually) throttling performance to protect itself.
First of all, this protection is fragile. High temperatures can still damage the processor and can also damage other components around the processor. I thus recommend that you run it as little as possible and that you get this blower replaced as soon as possible.
Hope this helps,