Leaving the computer overnight

oxymoron02 said:

Were those temperatures idle (system doing nothing) or under load (system operating at half or full capacity)?

To be honest though both are a little high in any scenario, particularly for your processor. Just out of interest are you using a laptop or a desktop?

Desktop. Read my second post..

so is this idle or under load? This is definitely too hot if idling. My phenom II idle CPU temp is about 48 degree C or so even when my a/c is off and ambient temp around 85 degree F.

pparks1 said:

Computers are designed to be able to run 24x7. If your fans are making noises after running for 24 hours straight, it sounds like they are on their way out and likely need to be replaced. I run a server at home that runs 24x7 for years on end.

Well I just replaced my fan near the end of June because the other one melted. LITERALLY. It was melted.. broken. One side - other side. It was literally looking cooked off.

The problem is most likely your CPU fan. The best thing I'd recommend is to download a program such as Open hardware monitor and check what speed your fans are going.

You still haven't answered two things that I asked, so I'm done here.

oxymoron02 said:

You still haven't answered two things that I asked, so I'm done here.

Sorry what were your questions?

There is no harm at all in leaving it on all the time, as long as you have the fans on good shape. The only real risk compared to normal operation is overheating. But if it can withstand a regular day of full working, it should have no problems over the night.
Moreover, all recent CPUs have thermal protections, so that it will shut down immediately if it overheats past of a safety point.
I personally leave many times my notebook powered on at night and when at the office, and actually am in front of it little time really. As of now, after a year of such usage, nothing seems to be failing so far.