G4 (Quicksilver) makes horrible noise (but works)

My G4 "Quicksilver" makes an awful shrieking noise. This began when I plugged it in after a move. The noise occurs even when the machine is turned off, and it stops when I unplug the machine. The noise changes somewhat when I turn the machine on or plug in a power-sucking peripheral (such as a firewire hard drive). So far the machine seems to work fine despite all this, but I don't know if I can expect it to keep working, and I really really don't like the sound.

Any ideas? Thanks.

sounds like a power supply problem, is it overheating?

Power supply would make sense.
How can I tell if it is overheating?
If it is a dying power supply, how big a deal is it to have this replaced? Is it worth doing on this older machine?
Thanks.

I had a quick hunt and they were asking 200 dollars for a power supply

I would take it out and have a look at it, might be something clogging up the fan (is it an electrical hum or a mechanical noise)

Get a vacuum and give it a good clean out (you could probably get a donor quicksilver off ebay for less than they are asking for the power unit alone)

http://cgi.ebay.com/AC-BEL-API1PC12...ryZ51044QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

You can find affordable stuff on ebay, just serach for quicksilver G4 rather then powersupply

Bad Ground Loop!!!!!

I read about it earlier....

I think I found it on wikipedia.com but I rebooted my computer and my history is toast!!!!!

I Googled G4 noise problem, you could try MDD Noise Fix also!

Hope that was helpfull!


;D

Since it does it powered down but plugged in it sounds like the noise is from the Power Supply. Have you checked Ebay for a used Quicksilver Power Supply? I am pretty sure that is causing your noise. If the machine is off the fan in the PS will not be spinning. All computers use Switching supplies. They can make all sorts of sounds especially if something is wrong.

It's is like a pretty high pitched sound?

If it's what I think it is be careful as if it blows the rest of the way it could take your board and everything else. Had a PC with a cheap Power Supply do just that. Loud noise, puff of smoke, Hard Drive, Zip Drive, Video Card, Motherboard all toast. When it went BANG it went into some over voltage that killed everything. Don't want to scare you but hate to see it kill your Mac. I will see what I can find and get back to you

Wow, dtravis, that's exactly what I was afraid of, that it will die and take the computer with it. Yes, it's a high pitched shrieking kind of noise, doesn't sound like a fan, and I don't hear any fan spinning when the machine is powered down anyway. Louishen, it sounds more like an electrical noise, thanks for the ebay tip.

Has anyone replaced a power supply on one of these? Is it hard to do?

I had a similar problem, and it was the Rotary Fan in the back that keeps the computer cool. It's almost like a loud obnoxious HUMMMMM right? Almost like the computer is vibrating?

Then that's the problem.

shreiking could be either a bad fan or a PSU

i would put money on the power supply. the shriek you are hearing is the voltage regulator and the power converter board getting ready to let go. the power supply has to take 110v AC (in the USA) and step it down to 3.3, 5, 12 and on some 25v DC to be correct for the system to use. if the voltage regulator/converter board goes bad with it connected to the mainboard and internals, it can short out and send AC current through everything inside the computer even with the system off. if you care about this system, then i wouldn't wait too long to get the power supply replaced.