Computer won't boot. Has power but no POST
Last night I closed the lid to put it to sleep, and just before it was closed I remembered something I wanted to do and opened it back up. It seemed to be asleep but would not wake up. I was able to power it down by holding down the power button. It would then not boot up. Pressing the power button causes the light on the front to come on. and the fans come on, but it does not go to POST. There is no startup chime, no video at all. I tried plugging in an external monitor and nothing. I’ve turned out the lights to be sure there was absolutely no video. I tried booting it in target mode and nothing. I tried booting from a system disk, and I can hear the disk start to spin for a short time but it does not boot and will not eject. I have tried pressing the eject key while booting I have tried letting it sit powered on for an hour. I have tried with power and no battery. I have tried battery and no power and I have tried both. I have tried removing the battery, holding down the power button for 10 seconds, then plugging in the magsafe adapter, then holding another 10 seconds, then trying to power on. I have tried reversing the two memory chips. I have tried both of them individually in each of the slots. I swapped the hard drive with another known working MB Pro and it works fine in the other one while the unbootable MB Pro still won’t boot. Is there anything besides a logic board that I haven’t tried? Any suggestions for getting the system disk out of the optical drive, other than putting the drive in a different computer?
Boot while holding down the space bar, that should toss out the disk. Attach a mouse boot while holding down the mouse button, same thing. If nether work you might try snagging the disk with part of the lead edge of a damaged or new blank disk & some thin double sticky tape.
Go over all your connectors, remove the battery and power main. Let sit overnight. Connect the magsafe and try a boot...
Didn't see you listed trying a "safe" (shift) boot.
Try different RAM or the RAM in a different machine.
If none of those work, I'd have to agree logic board... though from your description I don't know how you might have damaged it.
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