Computer fan/heat/noise questions

[CrusaderX]

I usually leave my computer (a Dell 4550 tower system) running 24/7. Yesterday I noticed that the machine was running louder than normal. Normally, I can hear a slight hum as well as the fan running softly, but this new noise sounded as if the fan was running louder than normal. I felt the back of the tower, which was warm to the touch. Not hot, as it didn't burn my fingers when leaving them pressed against the metal, but it was noticibly warm.

So I turned off the machine last night, then turned it back on in the morning. This morning, the machine sounded normal, though I only had it up and running for a short time before I headed out to work.

The tower is located in a cabinet that seems to accumulate quite alot of dust, so I'm assuming that the noise problem came from dust clogging the main power supply fan, and that turning off and turning on the machine cleared out whatever was temporarily clogging it. Like I said, I'm assuming this is what happened, but I don't know for sure. Later this evening, I'm going to unhook the computer and take it outside, open it up, and blow out any dust that's been accumulating in the machine for the past couple of years.

So, my questions...

Could the extra-loud fan noise be caused simply by dust?

Is it dangerous for the back of a tower to be warm to the touch? Should it always be cool to the touch?

 

[reveal]

I usually leave my computer (a Dell 4550 tower system) running 24/7. Yesterday I noticed that the machine was running louder than normal. Normally, I can hear a slight hum as well as the fan running softly, but this new noise sounded as if the fan was running louder than normal. I felt the back of the tower, which was warm to the touch. Not hot, as it didn't burn my fingers when leaving them pressed against the metal, but it was noticibly warm.

So I turned off the machine last night, then turned it back on in the morning. This morning, the machine sounded normal, though I only had it up and running for a short time before I headed out to work.

The tower is located in a cabinet that seems to accumulate quite alot of dust, so I'm assuming that the noise problem came from dust clogging the main power supply fan, and that turning off and turning on the machine cleared out whatever was temporarily clogging it. Like I said, I'm assuming this is what happened, but I don't know for sure. Later this evening, I'm going to unhook the computer and take it outside, open it up, and blow out any dust that's been accumulating in the machine for the past couple of years.

So, my questions...

Could the extra-loud fan noise be caused simply by dust?

Is it dangerous for the back of a tower to be warm to the touch? Should it always be cool to the touch?

It sounds like your fan may be going out. When you felt the back of the tower, did you feel the exhaust from the fan in the power supply? It could be the fan is going out on it.

Do you have a video card with a fan on it? I have an Geforce card that had the fan go out and it screeched like mad until I unplugged it and installed a new cooling system.

The tower being warm is not that big a deal. I would be more concerned about the noise.

 

[XCorvis]

Could the extra-loud fan noise be caused simply by dust?

Is it dangerous for the back of a tower to be warm to the touch? Should it always be cool to the touch?

Yes and No, respectively.

Computers get warm. This is normal, and I wouldn't be particularly worried about it.

Fan noise is usually caused by dust, as it gets into the fan and gums it up. If you can, take the fan out and dust it off. Blow out the case, if you can, to remove extra dust. Don't blow compressed air directly into the fan without holding the blades still - it can damage the fan by spinning it too fast. If the fan has bearings or a part that could use lubrication, try some WD40 (not too much). If nothing seems to help, try replacing it. Case and chip fans cost ~$15, but power supply fans are much more expensive (you have to replace the whole power supply unless you're an electronics guy and can safely take the PS appart).