imac won't boot

[rande]

Hi,
I've having problems with my imac. I was on it this morning and it just frooze up.
I tried re-booting and it would just come up with a white screen. I've unplugged, restarted.
Tried zapping. Re-booting on OS disk nothing. Tried a single mode. Sometimes I'll get a long beep. I've had it off for a while in case it a heat thing, but nothing. I do hear a clicking sound, but nothing more than a white screen.

I hope someone can help.
Thanks

[WiseGuy]

Sounds like your power supply may be dead or hard-drive failure. Did you try inserting your original OSX CD to see if it would booth from that?

I had something similar happen and it was the power supply. Time to go see Apple.

Best of luck!

[tiger_scout]

Sounds like your hard drive. I had freezing and clicking noises on my old ppc iMac. I replaced the hdd and it fixed it.

[Joe]

It sounds like the HD since you are hearing clicking sounds. You should be able to get it to boot into the Apple Hardware Test.

• For Intel-based Apple computers shipping with Mac OS X v10.5.4 or earlier, Apple Hardware Test is located on the Mac OS X Install Disc 1 and should be included with your computer.
• For Intel-based Apple computers shipping with Mac OS X v10.5.5 or later, Apple Hardware Test is located on the Applications Install Disc 2 and should be included with your computer.

To start up your computer in Apple Hardware Test:

1. If the computer is already on, insert the appropriate disc into the optical disc drive, then restart. If the computer is not on, turn it on and insert the disc as soon as possible after startup.
2. Press and hold the "D" key before the gray startup screen appears.
3. It takes a minute or so for Apple Hardware Test to start up and inspect your hardware configuration. While this is taking place, an icon appears on the screen:

I went through something similar recently though and I thought it was the HD but the Apple Hardware test pointed to a bad RAM chip. The hardware test should tell you exactly where to investigate.

[rande]

The next day it final came up; I let it sit there for along time.
I sent time taking as much off as I could.
I tried running disk utilities and is wouldn't let me select the HD it
said there was a hardware problem.
I had the OS disk in, but it didn't mount to it when it came up.
I changed start up disk but it wouldn't mount it.
I re-started zapped pram and ran single mode and ran that test; only once
didn't seems like there was a problem.
Re-booted and ran disk utilities and it was all fine.
I tried re-booting to the OS disk, but I got stuck on the language
window and wouldn't boot.

What does all that sound like? Is something going out or just needed some
overdue maintenance.

thanks

[WiseGuy]

Time to take it to an Apple store... sounds like the HD is failing. Someone else mentioned RAM, could be that? The guys at the Apple store can find out quick.

[Santa]

Clicking usually = Hard Drive is failing.......back it up quickly then get it to the Apple store.

[pmkprog]

If it is a Silver iMac, it could be a sensor on the board. Sometimes they tend to shut down from heat and a HD replacement is a temp fix. It might also be the main board. I have seen this issue in a 24" iMac. Once the sensor was replaced it has taken care of the problem. An authorized Mac repair should be aware of this.

[rich apollo]

My experience with the white screen turned out to be a bad RAM chip.

The clicking could indicate a problem with the HD or the optical drive.

[Joe]

The next day it final came up; I let it sit there for along time.
I sent time taking as much off as I could.
I tried running disk utilities and is wouldn't let me select the HD it
said there was a hardware problem.
I had the OS disk in, but it didn't mount to it when it came up.
I changed start up disk but it wouldn't mount it.
I re-started zapped pram and ran single mode and ran that test; only once
didn't seems like there was a problem.
Re-booted and ran disk utilities and it was all fine.
I tried re-booting to the OS disk, but I got stuck on the language
window and wouldn't boot.

What does all that sound like? Is something going out or just needed some
overdue maintenance.

thanks

That is almost exactly the symptoms on my iMac with the bad ram chip....except the clicking noise. I didn't have that. The bad ram chip did put my internal HD and my firewire HD into read only mode and once that happens they will not boot because the OS needs to write files to it and once it's in read only mode it can't do that so it won't boot. Once you get it to boot from another disk you can copy everything from the internal disk to another disk. So far I have not found a way to make those drive writable other than reformatting them.

Have you tried booting into the Apple Hardware Test yet? Even that was problematic for me but it finally did it and revealed the bad RAM chip. Removing it allowed me to re-install the OS and everything was/is good after that.