# iMac 2006 EMC 2124 no video, LED #3 not coming on.



## MangustOLD (Jul 9, 2012)

Hello,
So today I got an iMac from my friend. 
First it wouldn't turn on at all, no signs of life, so I have taken it apart, found diagnostics LED lights. When it is off #1 is on. When I turned it on #2 came on. Heard really quiet noise from power board. Fans had a little kick, just barely, maybe made 1/50 of a spin. And that was all. 
After that I took out power board and HDD, looked at power board for any signs of damages - didn't find anything. Plugged in all the wires but left out the HDD - tried to turn it on, the white light came on and the fans started working but no video as before, still the #1 and #2 LEDs are on. Replaced HDD no changes, still no video. And LED #3 is not coming on. 
Reseated RAM. Tried different stick. 
Disconnected power cable and held the power button for a minute. 
Thought about testing external video but don't have the cable or monitor, not an Apple guy. 
What might be the issue?
Thanks!


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## sinclair_tm (Mar 11, 2005)

Do you get the startup bong?


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## cl-scott (Jul 5, 2012)

LED #1 is for trickle/standby power and should be on as long as there is AC power connected to the unit and the PSU is good

LED #2 means that the PSU and MLB (main logic board) are communicating

LED #3 means that the video card has initialized

LED #4 means that the display has initialized

So you have a failure that is coming before the video card initializes.

Connect a keyboard and hold down Command + Option + P + R and see if you get a louder bong/gong sort of sound. The classic Mac boot chime. That would indicate that the unit has completed POST and is booting. If you get the boot chime, then combined with the fact that you have an LED #3, means that the first step in trying to fix the unit would be to replace the video card. However, given the age of the unit, I would question the wisdom of sinking any amount of money into it for repairs. Not to mention that replacing the video card would require removing the MLB, which is not exactly the most pleasant of tasks on those models (or any model iMac really).

If you do NOT get the boot chime, then the problem is likely going to be some bad caps on the MLB, or some other MLB failure, and then you REALLY don't want to fix it. That particular unit is probably rapidly approaching the Obsolete status with Apple. As it is it's definitely on the Vintage list, so the only place you could even get it repaired at all is in the state of California. Technically it would have to have been bought in CA, but I know for a fact that most CA AASPs will conveniently forget about this requirement. Apple has been eating their lunch for so long, they'll take business wherever they can find it.

My personal recommendation would be to sell the unit as-is on eBay for someone who might be looking for an LCD panel or some other component. Use whatever you get to offset the cost of a new computer.


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