Looking for Computer Hardware Specialist

[Greatguardian]

Sigh. So many things it could be. Without hearing the sound it's hard to make an accurate diagnosis. Posting a video of the PC starting up on youtube would probably be ideal.

[Finuve]

So it's not 'beeping' but rather 'buzzing', and very loud?

Some graphics cards that need their separate power connection usually (or often, every one of them I have ever had did) make an awful loud noise if the connection is not... connected, or the Power Supply is not providing the power thru this connection.

a possibility, try removing the GPU and booting off of on board video if you have it

[Runespider]

I had a few problems with a noisy fan like this, once it started running the noise would stop.

[Seriha]

Yeah, the case fan on the front of my tower likes to grind a bit on boots. I've tried spraying compressed air at it and around the vents, but without being brave enough to remove it, I usually just need to give it a minute or so before it quiets down.

[Zarchery]

That sounds like one of the fans, like something on the case, or CPU, or processor. Does the noise continue after bootup and if so how long?

[Vold]

Most common cause for a loud buzzing noise is too much wiring in a small case(or an overdone PC mod) and they get caught in the fans after you close it. I don't think any other computer noise to be found sounds anything like it. Do what others have suggested and keep the case open and start it up. Best way to diagnose the problem is to learn exactly where or the general area the sound is coming from and or see with your own eyes. Just don't go touching anything while it's plugged in and running unless it's to move the wires themselves out of the way but you'll want to shut down anyway and clamp them away from the fan on something.

Wiring butting heads with fans is the most awful sounding noise ever and it can really panic a person the first time they hear it(specifically on a new PC build and you're scared to all hell you did something wrong and just blew up your 1500+ dollar computer)From the sound of it you are actually using the computer so I can't believe it's a hardware issue beyond a fan problem. In my experience this sound and issue usually comes from the graphics or cpu fan as they age and collect dust. On start up they create this unearthly buzzing sound that lasts for a minute or so then stops after it gets going for a bit(usually on the "smaller" chips where only the basic small fan and heatsink are required, I like to think the bigger stuff can take more of a beating) I strongly recommend you deal with it sooner than later. I fried a GF card once when the fan died and I didn't know. I guess it's what lead to me buying a new one and ultimately moving FFXI to the PC when it could handle it several years back. The CPU though technically should just shut down the PC if it's in danger of overheating. But still I wouldn't wait for that obvious sign to occur.

Pro-tip for everyone, even the pros because they forget too: It's a good idea to dust out your PC case every 6 months, specifically the fan areas, especially the CPU and GPU fans and heatsinks. Don't be afraid of doing it. Just go buy some $5-7 compressed air cans and go to work on your computer. You don't need to go overboard with cleaning, just blow it out. If you need proper motivation on spending 7 dollars on air, it's better than having to buy a new computer. Dust build up is your computer's supreme enemy. Some have it better than others. All depends on your surroundings. My place is a dust factory. Dust is fricking born here and probably supplies 10% of the world's dust population.

[Dallas]

My money is on the power supply fan. The CPU fan is quiet.

[Runespider]

Or video card fan.

[Dallas]

A video card and CPU fan run more as the computer gets hotter. If they are obstructed, it sound like rattling, not buzzing. A power supply fan sounds awful.

My test, which I do not recommend to anyone is to set my finger on the flat surface in the center of the CPU fan. This stops the fan and the buzzing should continue. This is the only fan I feel safe testing, but I'm also crazy.

[Dallas]

I'll also point out that a noisy power supply fan has no significant impact on the computer. Replace it before you go mad, but not before.