Boots up with a black screen

Boots up with a black screen When i boot up my iMac the screen stays black the hard drive is running, makes beeping sound but, screen stays black.
Asked by: Guest \| Views: 219

Total answers/comments: 4

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mcgyver89 [Entry]

Sounds like your display is having problems. Can you shine a flashlight at an angle at the display and see the faint image of your desktop and icons? If you do that would imply the backlight has died. Either the CFL's or the power inverter has gone. If you don't see the image then you likely have a bad LCD or the LVDS cable has become loose.

mcgyver89 [Entry]

"I have the same issue.(iMac 2011 21.5”)

Symptoms: The last months fans run at full speed. Today morning when I was checking sites in Safari, the whole screen went white and the iMac restarted . After the restart the start sound was ok but the screen black and the fans at full speed.

Restarted many times but the screen always. I checked in the internet from another computer and saw many different causes for black screen.

I tried with external monitor in mini-displayPort and after 1-2 restarts it started on the external monitor

I also tried with this configuration pressing D at the boot to go to diagniostics but nothing was showing on the second monitor.

Then booted with the displayport and searched and found the TG Pro. Running it I saw temperatures around 30-40 deg C and the ODD and CPU fans at more than 4000.

I disassembled the machine and got out the logic board using instructions from ifixit. Sometimes on my pcs I use to repair, if they are old enough and have higher temperatures I change the thermal paste and are working very smoothly.

I did the same thing and changed paste on both the CPU and GPU.

Then after assembling and connecting it to power after some presses of the power button it started normally on the main internal screen and the external monitor as secodnary (ISSUE FIXED :) :) ).

I hope it will help other people."

mcgyver89 [Entry]

Hi guys, did this problem get resolved at all? I'm having the same issue at the moment... all 3 LED's working as they should, but no image at all... please help!

mcgyver89 [Entry]

Still having this problem, only my backlight turns on after like 5-10 minutes of waiting so it is not completely broken. Anyone have any idea of how to fix this problem?