Screen not working after logic board replacement

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2009年中 MacBook Pro 13" 一体化机

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Mik @mik20703

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发帖于: 2014年12月25日

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Screen not working after logic board replacement

Laptop would not boot up (stall at the Apple load screen then turn off, was overheating before total fail) looked up the issue on the net. Indicated the issue maybe the logic board, had issues getting the old one out (not the most technical) installed the new board with no major issues. Now the screen won't come on, and so I can't tell if the fix took, checked the cable connections they look good but no expert. Would like to get another 2 years out of this, any pointers?

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Rany @rany

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Step one would be to disconnect the battery, then try to re-seat the display cable after checking that the connecter on the board and the tip of the display cable are not damaged in any way (step 8 of this guide); then re-connect the battery and restart.

A- If the laptop is not restarting (fan not running), you have a dead logic board (assuming you have a known good and charged battery and/or you are connected to the wall charger, and everything else in your laptop is properly assembled, all the cables properly re-seated).

B- If the laptop restarts but you cannot see an image, try flashing a light on the Apple logo on the back of the screen. A spot of light will appear in the middle of the screen.

-B1- If you see something written, the LCD is turned on but there is no backlight (could be an LCD issue or a logic board issue). Best would be to try a known good display to be able to tell where the issue lies.

-B2- If you see nothing written, connect the laptop to an external display such as your TV via HDMI.

-B2-a- If you see an image there, it is likely you have a faulty display or a faulty display cable. Of course, you can try to change the display cable using this guide, but it is a bit of a pain. Then you will be able to tell if it is the LCD itself or the cable. Instead, same as in -B1-, I suggest trying on a known good display assembly if possible.

-B2-b- If you do not see an image on the external display, then your laptop is not "producing" any image, and you have a faulty board.

Hope I did not forget any steps..

指南

MacBook Pro 13" Unibody 中期显示屏更换

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中等

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1 - 2 hours

MacBook Pro 13" Unibody Mid 2009 Clutch Cover图片

指南

MacBook Pro 13" Unibody Mid 2009 Clutch Cover Replacement

难度：

困难

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Thanks for replying. Shone a light through the screen like you suggested, saw the Apple insignia on the initial boot screen but it didn't progress past that point and just shut off (original issue minus the lose of display) after approximately a minute. This is with newly purchased/refurbished part from Mac Medic. So could this not be a logic board issue and maybe a corrupted or failed hard drive and all I have done is made it worse (regarding display issue).

Does anyone know the symptoms of a failed hard drive? Read on a few forums that computer should slow down/show signs of failing or just quit but it was working fine, got new battery 6 mths ago only issue.

由 mekozlows 完成的 2014年12月28日

My bet is on option B1 above (board problem), especially that the screen was working fine before.

As for HDD issue, you can try booting from an external drive. But I usually like to start by booting in restore mode and use disk utility to repair the HDD.

由 Rany 完成的 2014年12月30日

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Thanks for replying. Shone a light through the screen like you suggested, saw the Apple insignia on the initial boot screen but it didn't progress past that point and just shut off (original issue minus the lose of display) after approximately a minute. This is with newly purchased/refurbished part from Mac Medic. So could this not be a logic board issue and maybe a corrupted or failed hard drive and all I have done is made it worse (regarding display issue).

Does anyone know the symptoms of a failed hard drive? Read on a few forums that computer should slow down/show signs of failing or just quit but it was working fine, got new battery 6 mths ago only issue. — mekozlows
My bet is on option B1 above (board problem), especially that the screen was working fine before.

As for HDD issue, you can try booting from an external drive. But I usually like to start by booting in restore mode and use disk utility to repair the HDD. — Rany

zzz @zzz30021 声誉积分: 7.6千 zzz 13 22 11 · Answer 1 · 2014-12-29T21:28:12-07:00

Is your problem no BACKLIGHT or no IMAGE?

Also, can you see the screen "activate" when it comes on? Meaning, when the laptop comes on, you can see the little ting that looks like ink moving around inside the screen?

You should have 3.3v on pins 2, 3, and 4 of the LVDS connector, and 27-40 on pins 21 ad 22.

If you have 0 volts on pins 38/39/40 you blew a backlight fuse. if you have 0v on pins 2, 3, or 4 you either got an F'd logic board or messed something else up that will be a PITA to solve.

Get measuring and let's get started.

EDIT:

Nevermind, I see you see an Apple on the screen. Just no light.

So we have two possibilities here.

a) You blew the backlight fuse, 0v on pins 21/22 of LVDS. If you have 0v here, 99% chance you F'd it up.

b) The board you got is a POS and not boosting. If this is the case, you'll see 12.6v on pins 21/22 of the LVDS connector. This means the fuse is intact since it is sending the main power rail through to the screen, but U9701 Is not using the inductor to boost it to the level required to power the screen. In this case. If this is the case, they sold you a faulty board, file chargeback and send it back. Or fix it if you want to, I'll help walk you through it, but this won't be easy or fun if you are new to this and you really should be reimbursed for the wasted time.

From what you posted this is an 820-2530 board, LP8543 Based, so there is a fighting chance of making this work. No proprietary APP001 BS!

I'll keep this data for future trouble-shooting! Thank your for sharing all this info..! — Rany
Hey guys thanks for the help and all. Had a couple issues; a bad hard drive and a failed connection on the new logic board. Thanks guys. — mekozlows

2009年中 MacBook Pro 13" 一体化机

Screen not working after logic board replacement

2个答案

MacBook Pro 13" Unibody 中期显示屏更换

MacBook Pro 13" Unibody Mid 2009 Clutch Cover Replacement

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