My iMac (in signature) is, I'm pretty sure, clogged up with dust causing it to overheat and go 'to sleep' in, well, in about 10 minutes. This, as you can imagine, makes working on it pretty much impossible. I've noticed some screws at the bottom of it where the air intakes are and, basically, I'm wondering if it'd be ok, or really really unwise to unscrew it and attempt to give it a clean? I'm intelligent, sensible and not completely hardware illiterate but am certainly nowhere near being even a competent technician with regards to these things. I'd be fine with a PC (taking casing off and having a go etc) but am really unsure about Macs as I've been told they're a nightmare when it comes to this kind of thing. What should I do? Thanks in advance PS: I'm really skint at the moment and don't think I can stretch to paying for this (warranty ran out last year) but, if I do come into some money, does anyone have any idea how much it might cost to get an Apple-approved professional to look at/fix this?