Weird iMac Hardware Issue

iMac 21.5" mid 2011. I installed new hard drive and reassembled. Power would come on, but would not boot. Thought I might have a cable that was disconnected, checked cables and all was good. So, instead of reassembling everything, I put LCD in place without screws and it booted up fine. Went to install the LCD screws and as soon as I pushed LCD inwards to tighten it down, the system shut down and would not boot. I removed screws, allowed LCD to lay in the frame, and it booted fine again.

So, it seems as though there must be something that is causing a short when I try to tighten down the LCD and the system shuts down, but without the screws and the LCD sticking out 1/4", system boots fine.

Any ideas?

Thanks

Brett

You probably have the video connector and cable placed wrong and when the screws are tightened, the connector loosens and that kills the iMac. We have seen this problem before. Go to www.ifixit.com and look very closely at how everything is orientated.

Thanks for the reply. I cannot find it on ifixit, so can you provide a like or tell me what to search for?

Best way to find it is inspect all the video connectors that go from the display to the logic board. The reason we are fairly sure that it's the problem is we used to have an Apple Technician that posted on our boards. He identified that particular problem helping other members to troubleshoot the same thing as you're experiencing.