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Sean Chandler
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How can I tell if my iMac logic board is dead

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my iMac will not boot. I have seen the symptoms of impending logic board failure bit I want to be sure

Edited by: machead3 ( )

Can you get into single-user mode by hitting command-s during boot? -- N

natalia47,

I cant boot into any mode at all I have tried all the PMU resets I could find online and no joy It wont even start up - it is like pressing the power button with the electricity in the house off From what I can find out, this model iMac is not covered by any extended logic board warranty like the G5 iMacs, so this is now an ex-computer

Sean Chandler,

I had an iMac Intel 2007 (2.4GHz) which has chime and sometimes able to boot fully to Snow Leopard after I open the casing and left the logic board lay outside the casing. Could this be logic board problem or the display board (GPU) problem?

Lai Soon Chong,

I have a similar problem, with my iMac 20 " EMC 2105, on boot up it doesn't make any chime, the optical drive spins (with disc stuck inside), I tried plugging in a regular (PC USB mouse and Keyboard) and nothing lights up on either one. I only have a wireless mouse and keyboard (APPLE) I am looking at an oversized paper weight at this point but really would like to try and fix it. I shut it down one day and the next day with no warning it just went to a total black screen. Any help out there?

Kim Catalano,

How far does it boot? Try running the usual variety of tests, from install disk, booting from external drive, booting to external display, running the apple hardware test, etc. Could just be a bad power supply too.

rab777hp,

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Chris Green
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Some symtoms of a dead logic board are as follows:

No chime

Fan activity

Drives spinning up

nothing displayed on the screen

no power throught USB (or the otherway around)

No Power Through firewire (or the otherway around)

abnormal noises

fans running at max speed

computer heating up abnormally

display image distortion (prior to fail)

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info
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Simple: Remove the Memory modules and if the unit does not give error beeps or flashing LED light, and the LED light remains stagnent you have a Logic Board Issue

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Ian Johnson
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So if my MBP isn't showing any response when I hit the power button... no light, no fan, no optical drive activity, no HDD activity, no screen activity, no chime...

What might this be? Doesn't matter what the power source is, same response with battery and AC. I thought it was a bad logic board, but this makes me hope otherwise.

Has there been an answer to this? Our iMac just died one day and we get nothing. they changed out the Power supply and still nothing. Now they are telling me it's the Logic Board (and $800 for the part - less than 30 days after the warranty ran out). Any thoughts???

Tammy Strey,

You said that you have tried the PMU resets. If you don't mind me asking, did you: 1) disconnect the power cord from the rear 2) Wait at least 10 seconds 3) Press the power button in and hold it. 4) While still pressing the power button, plug the power cord back in to the iMac. 5) Release the power button 6) Hold your breath and press the power button to start up your Mac. Hopefully that did something. If not, You may have failed capacitors on your logic board. Remove the back panel and examine the 26 (I think) capacitors that live on the logic board. they are small round cylinders with cross marks on top. if the top surfaces of the capacitors are dome shaped or have expanded you will need to replace them. Let me know and I can give you the challenging soldering procedure. This procedure is for the white G5 iMacs

randy3833,

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Cheney
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it's useful,mark it~

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