iMac stuck at startup

[ping255]

Hi, I'm having problems booting up my mid-2011 iMac. If I try to boot up the machine as per usual, it gets stuck at the white screen with Apple logo. I searched online for solutions (e.g. recovery disk etc.)

However, even after getting past the recovery disk and running checks on Disk Utility, the machine shuts down by itself without any warning.

Any idea what is wrong?

I am not planning to get a new iMac as I just got myself a MBP (which is solely for work purposes). Should I send it for repair? If so, where is a reputable place to get it repaired?

 

[incubus07]

Not entirely sure what the prob is with your current sypmptoms. But i had a similar prob but with the addition of bad graphics, initial diagnosis was faulty graphics, in the end they said they replaced the whole logic board.

Should I send it for repair?

why not? or would you rather have a very expensive and huge paperweight?

 

[szeli]

still got AppleCare? auto shutdown sounds like could be CPU/GPU thermal paste gone liao n causing it to overheat n shutdown.

 

[ping255]

still got AppleCare? auto shutdown sounds like could be CPU/GPU thermal paste gone liao n causing it to overheat n shutdown.

Nope. How much does it cost to repair?

 

[ping255]

Not entirely sure what the prob is with your current sypmptoms. But i had a similar prob but with the addition of bad graphics, initial diagnosis was faulty graphics, in the end they said they replaced the whole logic board.

Not very sure what's the issue too. Running "Verify Disk" shows that HDD is working fine.

How much does it cost to replace your logic board?

 

[Winston7222]

still got AppleCare? auto shutdown sounds like could be CPU/GPU thermal paste gone liao n causing it to overheat n shutdown.

Can also be the Fan not working well or completely dead.

If you adventurous enough, might wanna take it apart to diagnose and also clean out all the dust + replace thermal paste..

ifxit.com should have the necessary guide for you to do that..

 

[incubus07]

How much does it cost to replace your logic board?

i was lucky to still have apple care for it. Not sure how much the charges are

 

[Finishing_line]

Give this a shot to see if it works?

Turn On Switch

At the sound,
Press keys : Command + Option + R + P

 

[ahsiao80]

try attempting to boot-up your iMac in safe mode, if it works, shut down and reboot it again, works for me!

*It might take a few hours to boot-up to safe mode, mine took about 3 and i don't know why :/

 

[szeli]

try attempting to boot-up your iMac in safe mode, if it works, shut down and reboot it again, works for me!

*It might take a few hours to boot-up to safe mode, mine took about 3 and i don't know why :/

took 3 hrs? u might want to do a disk check.

 

[ping255]

Thanks all for your replies.

Yes I tried the above methods but they didn't work. I didn't know it takes such a long time to boot up in Safe Mode though, so I just switched it off after 15 mins.

Anyway I gave up troubleshooting myself and just sent it to QCD for checking. Will wait for them to call me then.

 

[ahsiao80]

took 3 hrs? u might want to do a disk check.

disk check was completed within seconds, so i highly believe there is no problem with my iMac