Backlight won't turn on

Question

iMac Intel 27" Retina 5K Display (Late 2014 & 2015)

모델 A1419 / EMC 2806 / Late 2014 또는 Mid 2015. 3.3 또는 3.5 GHz Core i5 또는 4.0 GHz Core i7 (ID iMac15,1); EMC 2834 late 2015 / 3.3 또는 3.5 GHz Core i5 또는 4.0 GHz Core i7 (iMac17,1) 모두 Retina 5K 화면 장착

571 질문 전체 보기

Sean H @hoganseand

평판: 35

2

1

게시일: 2016년 11월 30일

옵션

Backlight won't turn on

So after I upgraded my late 2015 iMac 27" and put it back together, the backlight did not turn on when started up.

Its just the backlight because I can see everything on the screen if I shine a strong light on it. I recently looked at the diagnostic LEDs on the logic board and the 4th one will not light when starting up. That leads me to indicate the issue is with the backlight board.

Any thoughts on how i can fix that?

Or, could it be an issue on the display side like the connections? The connections were good from what I could see.

I can't seem to find any info in 2015 iMacs.

답변되었습니다! 답변 보기 저도 같은 문제를 겪고 있습니다

좋은 질문 입니까?

예 아니요

점수 1

댓글 2개

Here's the collection of IFIXIT guides for your system: iMac Intel 27" Retina 5K Display Repair.

I would review them to see what you might have forgotten or mis-connected.

Dan 의 2016년 12월 1일

Yeah i keep looking . Ive tried to re do the whole thing multiple times and have the same outcome

Sean H 의 2016년 12월 1일

댓글 달기

답변 2개

선택된 답변

Dan @danj

평판: 479.3k

Self employed contract worker

35

329

971

게시일: 2016년 12월 2일

옵션

The only thing I can think of is you blew the backlight LED voltage regulator on the main logic board somehow. At this point I think you'll need to throw in the white flag and bring your system into an Apple Store or Apple authorized service center. Hopefully you can weasel your self into a free repair otherwise it could be expensive!

해당 답변은 도움이 되었습니까?

예 아니요

점수 1

댓글 1개:

Darn lol i didn't want to accept this fate but i was thinking the same thing

Sean H 의 2016년 12월 2일

댓글 달기

Here's the collection of IFIXIT guides for your system: iMac Intel 27" Retina 5K Display Repair.

I would review them to see what you might have forgotten or mis-connected. — Dan
Yeah i keep looking . Ive tried to re do the whole thing multiple times and have the same outcome — Sean H
Darn lol i didn't want to accept this fate but i was thinking the same thing — Sean H

Jordan Shababy @jordanshababy 평판: 13 2 · Answer 1 · 2019-09-02T05:48:28-07:00

Jordan Shababy @jordanshababy

평판: 13

2

게시일: 2019년 9월 2일

옵션

Hello! So a few years later- I also have a 2015 that has no backlight. I went through replacing the logic board, power supply and LVDS and had the same results: 3 leds on and the 4th is off. The only thing I haven't tried is another LCD. Thoughts? Thanks for any help!

해당 답변은 도움이 되었습니까?

예 아니요

점수 0

댓글 2개:

did you get to the bottom of this? - I've got exactly the same situation.. screens works when strong light shone but no backlight...

paul.lynch1 의 2021년 3월 8일

@paul.lynch1 - Sounds like you need someone to fix your logic board backlight circuit. I've seen a few of these for some reason the logic is more sensitive in this series.

Dan 의 2021년 3월 8일

댓글 달기

iMac Intel 27" Retina 5K Display (Late 2014 & 2015)

Backlight won't turn on

답변 2개

귀하의 답변을 추가하세요