IMac constant beeping and freezes when connected to the internet though wifi or ethernet

SOURCE: iMac G5 not connecting to Internet sometimes

hi,

Please follow the steps given at the below mentioned link to resolve the issue:-

http://forum.insanelymac.com/index.php?showtopic=25477

SOURCE: iMac won't power up

it might be the power source

SOURCE: IMac G5 no isight. Long beep at boot then flashing

hi there,

The question mark usually relates to the computer not finding a system. Usually a bad hardrive. The beep at the beginning can be faulty RAM.
I would suggest taking the computer to your closest authorised apple dealer for them to diagnose further.

Cheers
verb

SOURCE: iMac freezes on startup. Can't use safemode.

Safe mode just requires holding shift down during start up and if it starts up at all this should be possible. Once in safe mode, you should be able to use Disk Utility to Verify disk and Fix Permissions. To Repair disk or with/without safe mode you need to startup with your install disk and on the first screen or after selecting language, use options to select Disk Utility. You really should tell us the MacOS version--10.3.9 10.4.11 10.5.8 or 10.6 are current and tell us your install disk version, too. With safe mode you can use terminal to run fsck to fix the disk, read the man page. Alternatives include starting up in Target Disk Mode (command+t at startup) and using your computer as an external disk for another Mac by Firewire or possibly USB, fixing it using the others software. These methods in descending ease.
A now permanently dark screen would indicate a bigger problem and a trip to an Apple store for an evaluation. Tell us your iMac model--could affect whether you can easily savage your disk data in this case. -Ken

SOURCE: IMAC SCREEN FREEZES OR GOES BLACK.

same thing happens to me - most of the time it will just randomly freeze; occasionally i get an unresponsive black screen. this 24' aluminum imac usually has startup problems also - sometimes it will "gong" and nothing else; sometimes the apple logo will come up and then nothing else; sometimes it will load the logo and then spin for a few seconds and then freeze - the only option is to manually shut down. there is no rhyme or reason to it