What is my Mac trying to tell me?

Factual Questions
1

G5 Mac, OS10.4.11. Every few minutes it beeps, a very loud short high beep and a short low beep, with no space between them. It’s also been slowing down and locking up lately.

2

Does it sound kind of like an old hand held video game? It’s probably the hard drive. You’ll have to decide if it’s worth the trouble to replace it. Or you could get a FireWire HD and transfer your OS to it. G5s won’t boot from USB drives, but they will boot from FireWire.

3

Are these beeps coming though the speakers? If you mute the speakers, so you still hear it?

4

iMac or PowerMac?

Could be the hard drive. Also, as I recall the G5 PowerMac had a power supply that was notorious for “screeching” in certain situations.

5

I still hear it when the speakers are mute.

Doug K.: Yes, I’ve suspected it’s the hard drive.

6

PowerMac.

7

Is it still on the original drive? It’s gotta be the HD.

8

Here you go, an official Apple article on it, with sample sound files and everything
http://support.apple.com/kb/TS2033?viewlocale=en_US

It’s almost certainly the power supply - you may be up for a free replacement one.

9

2005 PowerMac G5s are officially vintage, 2004 and earlier are officially obsolete. On vintage models Apple will only sell parts to California residents. They don’t sell parts at all for obsolete models. Any free replacement opportunities are long gone.