pc starts up with a loud noise

[graymark]

ok, my computer starts up no problem but, sometimes, not all the time, it starts up with a humming noise which is quite load can some one tell me with this problem could be?

Keeping in mind that it is not doing this all the time about 1 out of 20 times and when I hit the reset button and reboots it normally stops, but I am a bit worried.
Thanks
Gray

[madfish]

more info on what your running for a system please

[Buji]

It could be your PS fan. Next time it makes the noise, stick a plastic straw or something similar into the fan grille to stop the fan from turning and see if stops. Mine does it all the time.Sometimes it will go for days as quiet as a mouse, other times it will act up a few times in one day.I keep an eye on my mobo temps and when they start to go higher than 7or8c above room temp I know the fan has stopped completely. The bearings are starting to go. Time for a new fan. http://www.sysopt.com/forum/smile.gif

[Target]

I have a system that does that, and I finally tracked it down to the second case fan I had installed into the box. Its the fan in the lower front of my tower. Its held in place with the plastic mounting bracket that came with the case.

Evidently, if the heat and humidity (or god knows what else) in my room is just right, the fan vibrates inside the plastic mounting mechanism until it is spinning fast enough to quit on its own.

For me, at this point its simply an annoyance that occurs once in a while and only lasts for a little while at boot up time. I've been meaning to put a thin film of some silicon on the outer edges of the fan frame to create a gasket-like interface which should both hold the fan tighter in the plastic frame, and provide a soft, vibration dampening, layer between the fan and the case frame.

Now, you could have a fan that is going bad as well, and you should investigate that. I checked mine and its fine, just vibrates sometimes at startup.

Give your fans a look. If they consistently do it at startup, it will be easier to figure out. Place pressure on the fan frame with your finger, and see if the buzz noise goes away. If so, you can then decide how to more securely mount the fan(s).

If you have narrowed down the sound to a fan, and if pressure doesn't resolve the noise, then the fan might have a bearing that is faulty. It would then need to be lubricated or replaced altogether before it totally fails.

While I may be leading you down the wrong path, its quick and easy to check.

Let us know what you find or what the status is.

EDIT:

Buji has a good point on the Power Supply fan. Hard to place pressure on it when its inside the PS, so sticking something in it to prevent spinning is a way to check that one. Would recommend that you place the pencil, or whatever, into the fan blades before you power it on and its spinning though.

[This message has been edited by Target (edited 06-01-2001).]

[HfdWolfPack]

Same thing was happening to me. I stopped each fan 1 by 1. Didnt help..Then I remembered the fan on my video card. That was the culprit.


check the fans

[eweruk]

Check the PS for sure and for any cables rubbing on the CPU fan.

[graymark]

Thanks guys, I found the problem thanks to you nice people. It was only a small piece of cord that some how got in there, took it out and problem solved.
Thanks Guys
Gray

[Target]

WOOT! Great news Graymark. Congrats on solving the problem and for letting us know.