Computer makes different sound when beeping when starting up PC

Hi everyone, new to the forum here.

A friend of mine built me a PC about 8 months ago. As the tower was getting a little 'warm', I decided to open up the tower and clean the fan using compressed air and also (what I think is the CPU, as it was just behind the fan) a little brush as it was covered in dust (the brush is kind of like the thing old ladies use when dying their hair on the roots, it's like a long black brush and isn't very hard at all, I've read that people have cleaned them using a toothbrush, I'd never do that).

Anyway, since then, my PC is alot louder than usual, it tends to make a noise which is like some kind of scraping sound and the 'beep' sound on startup sounds a bit different (hard to explain, but not as clear or healthy sounding, if that makes sense).

It seems to be running fine though, no problems at all but I am concerned about the loud noise (like a gentle scraping like sound) and how the beeping sound is different from before. It could just be a noisy fan and now that it's clean it's even noisier (especially when starting up).

As I know nothing about computers, I'm somewhat afraid that I've done something drastically wrong when cleaning the inside of my PC fan and the front of my CPU. Or it could have always been that way but I never really noticed it before (I'm very OCD about computers).

I should also mention that I didn't touch the hard drive when I cleaned out the components.

Should I have reason to be concerned? I'd hate to think that one day my PC would pack up on me as it cost me quite a bit and I do all my work and just about everything on there. Needless to say, it's very precious to me. It may just be a 'cosmetic' thing as everything seems to work just fine, it's just the noise and the weird beep when it starts up.

Thanks in advance-

Roygbiv.

I would check the CPU cooler to make sure you haven't moved a lead into the fans path. When you say you cleaned it with compressed air, did you stop the fan from spinning as you did it, or did you allow it to speed up as the air blasted it?

If you've allowed it to spin up whilst being blasted with air its possible you've let it go too fast and caused wear to the bearings of the fan, hence the louder noise.

When cleaning moving components (fans for example) using blasts of compressed air, it is essential to provide a means of stopping them from moving. For example, using the end of something like a screwdriver against the side of the blade will stop it from spinning. Spinning up fans faster than their designed specifications can cause premature wear to them.

With the side panel off, fire up the computer (do not touch any of the hardware with it running), and see if you can locate where the noise is coming from inside the case. It could be one of the fans, or it could be the CPU cooler fan. Also, have a good look around all of the moving parts and make sure that all wiring is away from fans -- including the GPU (graphics card) if one is fitted.

Ok thanks for the tip. I'll try it out later in the day.

Is this a serious issue though? I think the compressed air did actually make the fan move if I rememberer.

I just hope it won't cause any damage in the long run. I emailed a friend whose an expert in computers and he said that perhaps the screws weren't screwed in properly and really wasn't that serious, or else the computer wouldn't be able to boot up at all.

Here is his reply:

The first thing I'd do is make sure all the internal cards and any fans are secure inside. Just push them firmly into place (it sometimes takes quite a bit of pressure), the odd beeping is usually a sign that a card is in crooked and can't be accessed properly.

This is certainly not anything too serious mate, else the computer wouldn't be able to boot at all.

Failing that maybe a screw is in loose or rooked or not in at all, a fan may cause it to vibrate if thats true.