MacBook Pro Unibody - No Backlight - Logic Board Question

[Kevin117]

Okey, this fuse is blown, so need to get replaced.

Also saw the LVDS cable, looks like it is burned on the right side.

The connector on the logic board looks burned too. You need a way to inspect the area. I bought a small microscope from Harbor Freight and mounted a bright white LED on it.

http://www.harborfreight.com/25x-pocket-microscope-95883.html

I have all the same issues you have, which are mentioned many times in this thread. The expert (Dadioh) hasn't responded recently. I'm going to sit down one evening and read this thread through from the beginning, it's a monster.

Unfortunately to fix my connector on the board I think I'll need a hot air rework station $150-$200, patience, steady hands and nerves of steel. Or else I'll have to send it out to an expert repair place on eBay. ANYONE HERE IN THIS LINE OF WORK? Fortunately, all the parts required, fuses, cables, connectors, are available on ebay or elsewhere. The "MacBook Pro spill resulting in melted connector, blown fuse, possibly bad backlight IC" seems to be a REALLY common outcome of any spill.

I'm torn over sending my computer out for repair, or putting that money towards buying the rework station and trying to fix electronics as a sideline to supplement my retirement income.

 

[Pandanl]

Bought the parts that i need.

LVDS Cable 2x just incase
LVDS Connector, if replacing it is neccesary
2A Fast acting fuse 0402

Already removed the old fuse, so just need to wait for the fuse to come in.

Trying to clean the connector as good as possible now.

 

[Kevin117]

Bought the parts that i need.

LVDS Cable 2x just incase
LVDS Connector, if replacing it is neccesary
2A Fast acting fuse 0402

Already removed the old fuse, so just need to wait for the fuse to come in.

Trying to clean the connector as good as possible now.

Please post a how-to on soldering that connector. That's what scares me.

 

[l.a.rossmann]

Please post a how-to on soldering that connector. That's what scares me.

I will try to make a video of this if I ever find the time to compliment the QFN one.

 

[capitenjimmy]

2009 macbook pro 13 proc2.53 logic board

hi there ..i have 2.53 logic board 2.53 ghz and i can see video only on external monitor but only white screen on internal lcd ...is this a fuse problem ? is any body have the same problem (the lcd is good because i have my friend mac and we switch the parts problem is on logic board ),,,

 

[Dadioh]

hi there ..i have 2.53 logic board 2.53 ghz and i can see video only on external monitor but only white screen on internal lcd ...is this a fuse problem ? is any body have the same problem (the lcd is good because i have my friend mac and we switch the parts problem is on logic board ),,,

Not a fuse problem. Pure white screen means that the backlight is working. Most likely an issue with the lvds signaling from logic board to the LCD. Check that you a sending power (3.3V I believe) to the LCD and check other data signals. Could be bad connector or bad lvds cable.

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I'm torn over sending my computer out for repair, or putting that money towards buying the rework station and trying to fix electronics as a sideline to supplement my retirement income.

It takes practice. If you decide to go that route get yourself some dead circuit boards and practice removing and replacing components. For the small components on modern boards magnification is a must and a decent soldering iron with fine tip. Watch some videos of techniques online and practice on dead boards. Learning curve may be steep but might be something you enjoy doing. But it is a bit of an investment up front to get started.

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Hi to all Guys,
My macbook pro took some milk last year...and the backlight goes wrong.
Yesterday i decided to go ahead lokking for some solutions.
I point a flash light directly to lcd and i could see the apple while os booting up and then the desktop.
So it means the lcd is working and the problem is around LVDS and other chip...right?

So i zoomed on my LVDS connector and i found...loosing some pins as in the picture.

View attachment 406488

Is possible to do something without mb replacement, any suggestion?

15" model I presume since that looks like a 40 pin connector. The end pins carry backlight voltage if I remember correctly (not near a schematic right now). You need to replace the lvds connector. It is a delicate operation best left for someone with fine soldering capabilities. New connectors can be found on eBay.

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Not meow (cat related) "more". iPad has a mind of its own.

Here's the skinny....

Device: MacBook Pro A1278 i5 500gb (was 8G, but I downgraded to 4G)
Problem: No backlight, everything else seems to work fine now. I fixed a few other things like a bad trackpad cable, corrupt OSX.

Charges, runs for days on end, boots fine, audio, USB, wifi, all fine. Just no backlight.

The device was advertised as water damaged but there few visible signs. It must have been a very small quantity or was expertly cleaned. Just a few marks on the inner lower case near the power port.

What I did: After some research I found the fuse was blown and the LCD cable was burned on the motherboard side around pins 21-24 (common problem from reading this thread).

I changed the cable but in the process broke the glass (it was just in there too tight, even after using a heat gun for quite a while and suction cup. I replaced the glass and the cable.

As I was testing the fuse (which is bad) I accidentally shorted it out and the cable smoked again. So I'm back to square one.

BTW, I did not seal up the screen glass tightly yet, so there should be no trouble accessing the cable connector in there again.

The outstanding issue, who's cause is one I hope you're familiar with is, is... why does the cable burns up at the same point pins 21-24 area?

Is this a LED short or a problem with the motherboard side of the 30 pin connector? BTW, I have a spare identical machine which I could use for parts. It has a completely dead motherboard, severe water corrosion, but the lid and LCD look fine. And the LCD fuse is intact (zero ohms). If I was confident the smoke and sparks were caused on the LCD side I'd swap the lids out.

Questions: does this all sound familiar to you? What is the typical reason/s?

Thank you very kindly,
Kevin

The two pins that corrode or discolor are the pins that carry the backlight voltage. It is 27V which is by far the highest voltage on the logic board. When liquid hits that circuit gets pretty excited ( in the bad way). The reason those pins corrode is that corrosion is proportional to voltage. If you continue to run the board with the liquid or residue present then you accelerate corrosion on those pins. After liquid spill it is very very important to remove power and battery and clean residue before continuing to run.

 

[capitenjimmy]

macbook pro white screen

thank you for responding ,,here is the steps i done with this mac when i had my friends mac i tuck my logic board and place it on her frame with her battery hard drive and everything and same thing white screen ..so the problem is for fact the logic board and i don't see any signs of water on the board ,,

 

[peislander]

Verbose boot

thank you for responding ,,here is the steps i done with this mac when i had my friends mac i tuck my logic board and place it on her frame with her battery hard drive and everything and same thing white screen ..so the problem is for fact the logic board and i don't see any signs of water on the board ,,

Try booting in verbose mode.Hold down command & v while booting.See where it hangs or gives error.
Good luck

 

[capitenjimmy]

hi there i have same problem what video cip you replace?

thanks for your help , but finally i replace the video chip and solve the problem .

can you please show a photo of witch video cip it was ,,,i have same problem white screen and i now the lcd and the cable is good ,,

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Try booting in verbose mode.Hold down command & v while booting.See where it hangs or gives error.
Good luck

thank you i will try today ...

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Not a fuse problem. Pure white screen means that the backlight is working. Most likely an issue with the lvds signaling from logic board to the LCD. Check that you a sending power (3.3V I believe) to the LCD and check other data signals. Could be bad connector or bad lvds cable.

----------



It takes practice. If you decide to go that route get yourself some dead circuit boards and practice removing and replacing components. For the small components on modern boards magnification is a must and a decent soldering iron with fine tip. Watch some videos of techniques online and practice on dead boards. Learning curve may be steep but might be something you enjoy doing. But it is a bit of an investment up front to get started.

----------



15" model I presume since that looks like a 40 pin connector. The end pins carry backlight voltage if I remember correctly (not near a schematic right now). You need to replace the lvds connector. It is a delicate operation best left for someone with fine soldering capabilities. New connectors can be found on eBay.

----------



The two pins that corrode or discolor are the pins that carry the backlight voltage. It is 27V which is by far the highest voltage on the logic board. When liquid hits that circuit gets pretty excited ( in the bad way). The reason those pins corrode is that corrosion is proportional to voltage. If you continue to run the board with the liquid or residue present then you accelerate corrosion on those pins. After liquid spill it is very very important to remove power and battery and clean residue before continuing to run.

thank you for all i will check the voltage ,,the cable is good maybe connector,,

 

[kloofy]

Same yet different...

Have a mac pro 13" 2010. Initial water damage, did the whole alcohol cleanup. Screen sometimes goes on and other times not.
Upon startup Apple logo can be seen with flashlight through back logo but no signal when mac finally boots up, with external monitor connected, under displays it doesn't show up at all. only external monitor properties exist. Any thoughts?

 

[Mori3000]

Flux

Hi guys

I got tired of my Flux that i,m using, when i apply heat it become dark and like glue, and very difficult clean, is there any better than this?which kind of flux are you useing for soldering?

Thanks

 

[Mori3000]

So I discovered that the wled driver is located on the back of the logic board, however can anyone confirm that the wled driver used is LP8550TL/NOPB?

Image

Hi elitetek

I checked it up, the component you showed in the photo is the wLED driver, i had a board with back light problem which i got back the light by replacing that item.

But i picked it up from another Macbook air and i do not know where kan i purchase it.

By the way there is the same item on the Macbook air 2011 and after with another part number, it is LP8550, and i do not know if it is the same or not.

 

[Mori3000]

Macbook pro 2011

it is water damaged board, it workes but the only thing is the LCD connector which have problem,

Does any body know where shall i connect pin 1 and 8 which i have problem with.

 

[Mori3000]

Here is a photo of the Macbook air boards which i took from one to the other.

I took the wled driver from 820-3209-A to 820-3023-A.

Sorry the photo is not good

 

[aman0607]

MacbookPro 2010 No backlight

Hello,

This is about MacbookPro 13 inch 2010 model

I have been reading this thread and I am stuck at a similar situation where I not getting any backlight on LCD. Let me tell what exactly happened-

My laptop was overheating. So i decided to replace the thermal paste. Opened the laptop and saw there was hardly any thermal paste on the heatsink. Packed everything up and turned on the laptop but no screen. I shined the light through the apple logo and saw the picture on the screen. So at this point I am not sure if the cable is bad or the fuse is blown. If the cable is bad I can replace it. If the fuse is bad then I might need somebody's help walking me through it. I saw a lot of people helping on this thread. Please help me because I am out of budget to take it to apple.

 

[Dadioh]

it is water damaged board, it workes but the only thing is the LCD connector which have problem,

Does any body know where shall i connect pin 1 and 8 which i have problem with.

Pin 1 is ground so you could live without it. But pin 8 goes straight to the Cougar so you are going to have to find what via it connects to and try to link to that.

See attachments.

 

[Dadioh]

Hello,

I have been reading this thread and I am stuck at a similar situation where I not getting any backlight on LCD. Let me tell what exactly happened-

My laptop was overheating. So i decided to replace the thermal paste. Opened the laptop and saw there was hardly any thermal paste on the heatsink. Packed everything up and turned on the laptop but no screen. I shined the light through the apple logo and saw the picture on the screen. So at this point I am not sure if the cable is bad or the fuse is blown. If the cable is bad I can replace it. If the fuse is bad then I might need somebody's help walking me through it. I saw a lot of people helping on this thread. Please help me because I am out of budget to take it to apple.

Search the thread and you will find the fuse location. The 2009 and 2010 MBP13" are in the same location. Top side of the board, below the WLED driver. Look for small 0402 fuse with white dot. Should be zero ohms resistance. If it is blown you measure Megaohms.

 

[aman0607]

Search the thread and you will find the fuse location. The 2009 and 2010 MBP13" are in the same location. Top side of the board, below the WLED driver. Look for small 0402 fuse with white dot. Should be zero ohms resistance. If it is blown you measure Megaohms.

Thanks for replying. I really appreciate it. I found the 0402 fuse with white dot. So will I be able to use a regular 12V multimeter to measure it or do I need to have something else?

Also- If the fuse is blown, is there any video or walkthrough on replacing the fuse (soldering and stuff)?

 

[Dadioh]

Thanks for replying. I really appreciate it. I found the 0402 fuse with white dot. So will I be able to use a regular 12V multimeter to measure it or do I need to have something else?

Also- If the fuse is blown, is there any video or walkthrough on replacing the fuse (soldering and stuff)?

A multimeter set to measure resistance. Measure with all power removed from logic board.

The video below shows the soldering technique. I use two soldering irons to remove in a pincer fashion.

http://www.youtube.com/watch?v=66GV4OuShzI

 

[m3rcurial]

Greetings all!

First want to say thanks for the information in this thread.

Recently my bag strap snapped, dropping my bag to the ground, smashing a bottle of cider in the process. My bag also contained my 15" Late 2011 MacBook Pro.

Dried said MBP out with rice for a couple of days, turned it on and it worked fine, however the screen was still full of liquid, to the point where I could barely read the screen.

After about 30 seconds, the backlight flickered and went out, but the screen was still visible and working under external light.

After some research I decided to replace the LED display, as I assumed the backlight had died due to the liquid damage.

Despite replacing the LED display, I am still having the same issue... The LED display works, but the backlight does not.

Having read this thread I now assume it is 'the fuse' that has gone... I was wondering if anyone (Dadioh) could possibly point out to me where 'the fuse' is on a 15" Late 2011 MBP, so I can test/replace it?

Thanks in advance.

 

[Dadioh]

Greetings all!

First want to say thanks for the information in this thread.

Recently my bag strap snapped, dropping my bag to the ground, smashing a bottle of cider in the process. My bag also contained my 15" Late 2011 MacBook Pro.

Dried said MBP out with rice for a couple of days, turned it on and it worked fine, however the screen was still full of liquid, to the point where I could barely read the screen.

After about 30 seconds, the backlight flickered and went out, but the screen was still visible and working under external light.

After some research I decided to replace the LED display, as I assumed the backlight had died due to the liquid damage.

Despite replacing the LED display, I am still having the same issue... The LED display works, but the backlight does not.

Having read this thread I now assume it is 'the fuse' that has gone... I was wondering if anyone (Dadioh) could possibly point out to me where 'the fuse' is on a 15" Late 2011 MBP, so I can test/replace it?

Thanks in advance.

I haven't had the pleasure of working on a late 2011 15" yet. But if you can post some clear photos of the logic board both front and back near the lvds connector I could try and locate it. Also, if all you did was rice dry it then there will still be lots of cider residue on that board. It really needs a good cleaning as well.

 

[m3rcurial]

Thanks for your speedy reply.

Nothing inside felt sticky, and I think the top casing and screen took the brunt of the cider, however I haven't fully removed the logic board yet and checked underneath for residue, and going on other unibody 15"s the fuse is probably on the bottom, so when I take it apart to take the pictures tomorrow I will give it all a good clean with isopropyl and a soft bristled brush.

 

[Eyeage]

@ Dadioh

So, we've arrived at an issue. Since you seem to work on these a lot I'd figure I'd ask what you think (to confirm my suspicion). So, this macbook pro is working perfectly (since replacing the fuse), like it's brand new, when it's plugged in. When it's unplugged it becomes laggy and slow to respond. Video gets choppy as does scrolling web pages.

I've tried all the normal stuff:
Reset Nvram
Reset SMC
Repair permissions
Repair HD

Battery "appears" ok, as do all of the repair tests. Still, this is most likely a bad battery, right? What other options can I try at this point?

 

[Fabbry]

@dadioh

Can u help me finding schematics of my mb ?
Also helping me to find the fuse ?

My mb is 820-2533 B.

Thank you!!

 

[Soh5757]

Thanks for the help

First off, I wanted to thank you, Dadioh, for all the great help that you have offered everyone. It's awesome that you're doing that.

Like everyone else, I'm having back light issues. Simply put, you turn the computer, the lights come on for a split second, then turn off. from reading this through this post, I understand it is most likely a capacitor that is causing the issues. However, out of the two that I see on my board, they both give a positive signal for continuity. I didn't want to waste your time by asking the same question everyone else is asking, but I can't find anyone who has asked about my logic board, being a 820-2279-A. It was bought in July of 2008. I also remember reading about the QFN package. I also cannot find that. I truly hope I don't have to replace that, but if need be, I can. I have the tools at college, luckily. I have uploaded some photos of my Logic board for you.

http://postimg.org/image/6v2djdb0l/

http://s8.postimg.org/49rc2y0it/IMG_1531.jpg

http://s8.postimg.org/4wlneq811/IMG_1532.jpg

http://s8.postimg.org/hk604zcbp/IMG_1533.jpg

http://s8.postimg.org/mb5vn055x/IMG_1534.jpg

Any help would be great. Thanks again