My imac 21.5 10.6.6 doesnt starts up it freezes on the white screen w. the apple and the loading bar or circle!

Sounds like faulty screen.

Here's a video Charles East suggested as a solution to your problem from YouTube:


How To Fix White Screen On Your Mac

Reboot the computer while holding the V key. This will boot in verbose mode and show you the specifics of the boot issue.

Try two or three times, make sure there are no add ons usb

restart from your original cd/dvd that came with the computer, then open disk utility and run disk permission and disk repairs from the utility
Kev. www.apple-core.co.uk

Before buying one, call Apple (1-800-My-Apple) I just got my screen on my iMac (out of warranty and about the same vintage) replaced for free. There is a Special Warranty for this problem. It my not be the same for yours, but try.

First hold down the right hand shift key down when you start, this does some housekeeping, The next step is if you have an install disk or tiger disk then start up from it by holding the "C" key down when starting and inserting the dvd, if this loads then go through the install menu, dont worry you do not need to actualy install just select language and then you get to a screen where you can select utilities from the menu bar, then select disk utility and repair permissions, after that do a repair disk then quit disk utility and change the startup disk back to the hard drive and restart, if for some reason you cannot repair the disk, this refers to the catalogs it uses to keep track , not the data itaelf, in that case you need a 3rd party utility like Disk warrior.

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

I have one doing exactly this at the moment. It had gone to sleep and the fans were going like crazy. I think it is a Motherboard failure (it happened with many G5 iMacs), this one has been replaced once already, and I can't actually get it to install anything. I'm taking it apart tomorrow to see what I can find inside. If I fond anything I'll let you know.

Few Questions answered can help me out.
1)Did you update the OS

2)Did you install any drivers recently

3)did you install any software's

4)is any external devices connected when facing this problem

5)did you put new RAM inside

6)did you try to boot from the DVD disk 1 and repair hard drive using Disk utility

This can easily help to resolve the problem