[k1ttenface]

When i got starcraft 2 yesterday i was having problems with overheating so opened up my case an went over everything with compressed air, including blowing the dust out of both fans. When i turned it back on the fan started making a loud noise like it was going really fast (i dont think that somthing had gotten in the blades because the fan it was coming from is in an unopanable metal box with a sticker saying (unservicable parts, do not open).

I stopped the blades with a pen to make sure that it was the fan making the noise and when the fan started moving again it was without the noise it was making before and rebooting the pc resulted in it starting up fine. However, i just started up this morning and the exact same thing happened. I opened up the pc to look for abnormalities and found nothing and hooked it back up and stopped the fan with a pen again and that fixed it and it has stayed fine after rebooting again. Any idea what has happened?

[win2kpro]

The box you are talking about is the power supply. It's most likely that a bearing in the fan in the power supply is beginning to fail. As the power supply heats up the internal fan or fans in the power supply automatically increase speed to cool the unit.

If it is a fan bearing starting to fail eventually it will start to make a lot of noise or fail completely.

[k1ttenface]

While that does make sense, it's not that old, it only started after i cleaned it (fairly sure that was the cause for whatever reason), and that it does it on startup (so wont be going faster due to heat) and stops as soon as i stop the fan. None of it would suggest that was the case.

[win2kpro]

There's nothing I know of on a fan that can cause it to make noise of than a cracked or broken blade, bad spot on the bearing or slightly bent fan shaft.

If you blew compressed air on the fan blades without holding the blades to keep them from moving, compressed air can cause the blades to overspeed and damage the bearing.

The age of the fan is not a factor. I've seen fans last for years, and have also seen new fans defective right out of the original packaging.

[k1ttenface]

Yeah, i guess that could be the problem if blowing compressed air on it could cause damage, although it's still a mystery why it stopped, i guess i'll havta watch it and see what happens in the long term.