Hey. 
 
So, I'm wondering what has happened: I have an old (~2008) fat PS3 with a custom 500GB HDD. In the past it was always perfectly silent, and only started getting noisy when I played graphics-heavy games like GTAIV. 
 
Now, however, it turns on the fans ~5-10 minutes after boot. Even if it's just standing on the XMB doing nothing or if it's playing a movie. 
 
I'm assuming it's dust-related, but how do I go about doing a complete clean of the damn thing? I've tried vacuuming the vents, canned air and that sort of thing, but that doesn't get to the inner parts of the PS3. Do I have to *gasp* ...open it? 
 
Also, I'm pretty sure the warranty has expired anyway.

If it's warm outside then there's your problem, plus the PS3 needs a lot of room to breathe, it needs at least a 12 inch gap behind it or more if you want a quiet console, especially during the heat. Also, don't use a vacuum, it causes static to build on your circuits, which isn't a good thing.

It's probably warm, you should still vacuum it to help it out a little bit, but if you live in a palce that's going through an intense heat wave or something that may be the reason. Either way its overheating.

Gta 4 killed my ps3, it's too much graphics for it, which will create heat on the gpu, then the fans will go up to cool it. I'm just theorizing, i'm not sure, however it's better than an overheated gpu.  

turn it upside down
hold the ON button in
that should initiate the fan test
it removes dust
see if it helps

my ps3 slim cracks sometimes lol

Well I was gonna say to clean the fans but you already know so I guess call Sony and ask for help.

" my ps3 slim cracks sometimes lol "

Mine started making a weird noise, so I reset the system back to original settings (no I did not erase everything) and the noise went away. I, then, fixed the things back how I wanted it and haven't had a peep out of it since. Try it.

I had the same issue when I purchased a used PS3 over eBay. I opened it up and vacuumed out all the dust which caused the fans to run much quieter. Might want to try that if you don't have a warranty anymore.

The thing is once a vent is dirty you will not get it clean ever again. Once the noise start humming you have to replace the vent.

Take it to a repair shop and have them install a new one.

" @Zajtalan said:

" my ps3 slim cracks sometimes lol "

 hey that always happens to my ps3 slim only after i finish playing a game & turn the ps3 slim off...it makes some small cracking sounds ! anyone know whats it doin?? "