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jackie-chan

macrumors newbie
Original poster
Nov 12, 2014
7
4
Hey guys, I have another issue with my mid 2011 27' iMac a1312 screen not turning on.

The computer boots and the OS is working, but the screen remains completely black. Even when shining a flashlight on the screen, there is no visibility at all. The screen had been blinking to complete black for second here and there through out the day for about 6 months before this issue.

Inside the iMac when powered on 2 of the 4 LED indicators are lit up. From reading what others had said that means the screen is not receiving power if I'm correct.

After digging around on the forums I found a couple possible solutions but still not 100% sure what the problem is.

I just replaced the backlight inverter board ($20) and it still doesn't work. I also ordered a new v-sync cable to replace but I don't think that's the issue after reading around the forums more.

Do you guys think it's just something in the LCD screen that blew out?

I'm going to order a new screen on ebay soon and will update if that fixed it or not.

Any feedback is greatly appreciated!

IMG_4333.JPG
 
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did you reconnect the power to the screen at the top? Its the last thing to plug in by the power supply, hopefully you didnt rip it when taking it apart the first time. should be upper left asyou look at it.

power supplies in the iMacs have been known to go bad also. I have seen a few.
 
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Heya, thanks for the reply!

But yes, I definitely did plug the power in the upper left back in.

My new LCD just arrived this morning, unfortunately after hooking it up it doesn't work either T_T

Really have no clue what the issue is now... Maybe just replace the power supply like you said? I guess I'll give that a shot since it only costs about $30 to order one. If that fails I'm just gonna take it in, not worth all this hassle and time for me anymore. I'll update again after I replace the power supply.
 
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Its the video card most likely I would guess as it is a known failure point. Do a search on oven reflow, and go to ifixit for take apart to get the card out, and reflow the card. Ive had about 75% success in reflows. Sometimes it lasts, sometimes it doesnt work and you just need a new card.
 
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Go to an Apple store to get it dialogistic and see whats wrong with it or sell it broken on eBay and save up to get a 2012-2015+ model that should not have this design issue which I would recommend.
 
Its the video card most likely I would guess as it is a known failure point. Do a search on oven reflow, and go to ifixit for take apart to get the card out, and reflow the card. Ive had about 75% success in reflows. Sometimes it lasts, sometimes it doesnt work and you just need a new card.

Interesting, I've never heard of this. Pretty crazy. Thank you for the tips
 
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