Hi, so ive had my new cyberpower computer for about 2 and a half mouths. But for some odd reason ive been noticing a few problems showing up on my system. The first problem is ive noticed a 2 degree jump (unloaded) in my case ( 30c to 32c) and a slight jump in temperature for my cpu. Now its hard to say if its the fans seeing as how its summer and it dose get hot in my home. but then i started getting this really wired grinding noise with my case fan. The problem only happens when i started up my computer and after about 5-8 secs the sound goes away. if i reset my computer or put it to sleep right away it will not make the noise. So it seems the problem only shows up when i leave my computer off or asleep for more then an hour. Note i have cleaned the fans out with compressed air (noise is still there on started up).
Cleaning the fans with canned air is like taking a shower. If you get sick from not doing it for months, one shower isnt going to make you instantly healthy.
Regular cleaning can prevent things from happening. Try dusting it every couple days for a week and see if the noise started reducing. Also you probably want to dust out the CPU and GPU fans, and any heatsinks on the motherboard every month or so, depending no how dusty your room is.
Sometimes, weird noises are the result of resonance - all devices have a resonant frequency. At this frequency, strange resonant noises will be produced. However, at higher or lower frequencies (or speeds) the noises will disappear.
A simple way to test for this is to place your palm on the side of the computer case. If the noises disappear, then resonance is the culprit. To solve this, try fixing a piece of flat plastic on the inside of the case side cover with adhesive tape.
In your case, the fan is attaining resonant speed during startup. It really isn't a problem. If the noise persists, you have a solution; just described.
I had a similar startup fan noise problem, and it was caused by the Corsair RAM fans. I relocated the fans slightly and the noise went away.
Check your fans for 'Squishiness',
By that I mean put your finger on the centre of your fans, and push gently to make sure its seated correctly on its bearing, they can work loose in transit and over time in use, another option to consider is your hard drive/s, one of mine clarts right up on Boot, then it seems to 'warm up' after 20 seconds or so, I suspect its a drive failure warning hehe
erm, just off to back up my files.
*Edit, wandered off for a few minutes and thought about it, I am leaning more now to it being your hdd, mines almost exact same symptoms, after using for a while, (I.E. its 'warmed up') I can shut down and next boot its fine, its first thing in morning that it Grinds most*
I'd squish your fans first though, I do mine weekly (same as the hoovering hehe)
I face similar problem before with my pci fan the noise remains for 2 min every time I turn on my pc but I put some Grease inside the moving part of the fan and every thing gos fine the grease or oil reduce the friction between the moving part of the fan and reduce the noise or stop it at all
but be careful don't put allot of greasing oil just some drops It will be better to take your fan out and do it