iMac-Keeps restarting after power-up.

Question

Level 1

33 points

iMac-Keeps restarting after power-up.

After power up, it would get to a point where error would display. Image attached- "Your computer needs to restart. If it does not restart automatically............." After a while, the screen would fade to grey and would keep restarting. After reserching, I tried all diagnostic keystrokes and got no function. It didn't seem to find OS and ruled that maybe the HD was dead. I tried installing OSX 10.8.5 and no luck!..ℹ.it would get to a certain point, as though it was loading the OS and then stop. I replaced HDD thinking that this would be the fix, but again...no luck. It would just behave the same as ℹ. I never give up, but I'm ready to throw in the towel...

Would appreciate any help.

MacBook Pro, OS X Mountain Lion (10.8.5), iPhone 5s, Mac Mini, iPad

Posted on Feb 24, 2014 1:55 PM

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Answer 1

Feb 24, 2014 1:58 PM in response to Ruben MZ

Appears to be a kernel panic message. Check out the following links & do the necessary.

OS X: About kernel panics

User Tip: Kernel Panics? Don't panic too!

How to troubleshoot a kernel panic

http://support.apple.com/kb/PH11342 OS X Mountain Lion: Use Apple Hardware Test

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Answer 2

Ruben MZ Author

Level 1

33 points

Mar 19, 2014 7:19 AM in response to Baby-Boomer-USofA

Tried hardware test and all startup key combinations and still nothing. I opened up the housing and did notice something that seems abnormal with the power supply. I noticed a white residue on PS circuit board and wonder if this may be leakage from the capacitors? See pix.

I'm taking a stab a replacing the power supply and hope that this may solve the issue. I'd appreciate any advise or comments.

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Answer 3

Ruben MZ Author

Level 1

33 points

Apr 17, 2014 7:33 PM in response to Baby-Boomer-USofA

I took my iMac to the apple store and after they ran a hardware diognostic and checked out OK. Then proceeded to start up in single user mode to do further checking and diagnostic. The technician then told me that the GPU was bad. I proceeded to order a GPU from Gainsaver.com and replaced it. Started up, kept my fingers corssed and all of the sudden---the same dimming screen leading to the same kernel panic!

Arghhhhhhh!

I made an appointment at the apple store and had th iMac diagnosed again. This time, I was told that most of the time the kernel panics were generated by "bad RAM"...The technician then took it to the back to replaced the RAM but to no avail,...same familiar screen. Technician then recommended replacing the logic board.

At this time, I've had the this iMac opend about 4 times that it's a breeze to open and put back together. So, in conclusion: I'm ordering the logic board tomorrow to replace and will write an update with the result.

Wish me luck!

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