MacBook Pro Unibody - No Backlight - Logic Board Question

[Dadioh]

@Dadioh

Thanks for this thread. My friend's child spilled some water on his MBP, and it has the "no backlight" issue. Researching led me to this thread, and I told him I'd "try" to fix it. Initially it didn't even turn on until I took it apart and cleaned the board with alcohol. That led to having everything but the backlight.

So, after a couple of weeks (he took it to bestbuy who quoted $1400 fix), he gave it to me and said to see what I could do. Upon taking it apart this time, the fuse with the "P" on it just came off when I touched it (lightly). Obviously corrosion/rust took hold.

Now, it appears I have another little piece missing, and it looks like the one contact for the fuse is missing. I've attempted to clean it to no avail. You can see from the picture that the one contact is still dirty (and only half looks connectable), but the other one is dull, and doesn't appear to have any metal under magnification. Also, it appears that another little piece is missing as well (right next to it, in a line of similar little guys). It also appears that the leads for the cable my be damaged.

I was hoping you could take a look at this and give me your assessment. Thank you.

That is a pretty heavily corroded board

I grabbed a picture of that board from a few pages back in the thread and compared it to your picture. There is a set of unpopulated pads next to the fuse so you may not be missing a part other than the fuse. The immediate question is... where does the missing fuse pad normally connect? On the schematic it indicates that it goes to pin 4 of Q9706 but you will need to determine where that is on the board and see if you can add a mod-wire connection from the fuse to that point. Will require some decent soldering skills and tools.

 

[Eyeage]

That is a pretty heavily corroded board

I grabbed a picture of that board from a few pages back in the thread and compared it to your picture. There is a set of unpopulated pads next to the fuse so you may not be missing a part other than the fuse. The immediate question is... where does the missing fuse pad normally connect? On the schematic it indicates that it goes to pin 4 of Q9706 but you will need to determine where that is on the board and see if you can add a mod-wire connection from the fuse to that point. Will require some decent soldering skills and tools.

Seems a bit more involved than my capabilities will allow. That said, I'm not against a challenge. If it doesn't work I'll either sell it on ebay or buy a new logic board and install. No reason not to give it a shot.

Does it look to you like the pad for the fuse is missing as well? Is there a chance that it's just SUPER corroded. How would you suggest trying to clean it (a few would be helpful, as I've already tried a couple)? I noticed the other board picture too, but since they were painted on that board, and these are copper I'd figure I'd double check.

Is it worth trying to fix this, or should I just give my friend the "new board vs ebay" options. I'm a novice at this, as I've only fixed a couple of radios with soldering (much bigger than this). I don't have a microscope, either. I"m using a large magnifying glass. It lets me sell well enough... but obviously it isn't great.

Anyway, thanks for your time. I'm just trying to help a friend.

 

[Mark83]

Hello,
I have a MacBook Pro Unibody 15" mid 2009 with 2,66GHZ Core 2 Duo.
It works all fine, but the backlight from the lcd is not working.
I tested a other LCD with an other LCD-Cabel, it is the same, at an extern display, the MacBook Pro works without problems.
Any Idea what it is?
thx for helping

Mark83 from Germany

No answer?

 

[Dadioh]

Seems a bit more involved than my capabilities will allow. That said, I'm not against a challenge. If it doesn't work I'll either sell it on ebay or buy a new logic board and install. No reason not to give it a shot.

Does it look to you like the pad for the fuse is missing as well? Is there a chance that it's just SUPER corroded. How would you suggest trying to clean it (a few would be helpful, as I've already tried a couple)? I noticed the other board picture too, but since they were painted on that board, and these are copper I'd figure I'd double check.

Is it worth trying to fix this, or should I just give my friend the "new board vs ebay" options. I'm a novice at this, as I've only fixed a couple of radios with soldering (much bigger than this). I don't have a microscope, either. I"m using a large magnifying glass. It lets me sell well enough... but obviously it isn't great.

Anyway, thanks for your time. I'm just trying to help a friend.

It looks like the top pad is missing. You are looking at the "pit" in the FR4 circuit board material left by the missing copper pad. Best thing to clean with is 99% pure isopropyl alcohol and a new toothbrush.

Repairing it means using fine gauge wire to solder from the fuse end over to wherever it is meant to connect to. I am not sure if a magnifying glass would give good enough magnification for such delicate work. I would try and find someone who has fine soldering skills to do that type of repair.

If you decide to sell send me a PM because it might be something I would be interested in.

Cheers

----------

No answer?

If another, known good, display does not work then it is your logic board. The 2009 MBP 15" fuse is located on the back side of the logic board. I think there may be some pictures further back in the thread but if you get stuck let me know and I will post a picture of the location.

 

[DSmaC]

Dadioh you are the bomb.
I replaced the blown fuse and the other part you ID'd for me and I am now posting this from my resurrected 09 15 inch Macbook Pro that I got off Ebay cheep.
Now that it is worth working on I'm going to go back in and do a full clean and replace the thermal paste.
What do you know about sound cards?
Got a 13 inch 2010 Macbook Pro that doesn't see any device present thus no sound or mic.
Thanks again for the component level thread/help.

 

[Eyeage]

It looks like the top pad is missing. You are looking at the "pit" in the FR4 circuit board material left by the missing copper pad. Best thing to clean with is 99% pure isopropyl alcohol and a new toothbrush.

Repairing it means using fine gauge wire to solder from the fuse end over to wherever it is meant to connect to. I am not sure if a magnifying glass would give good enough magnification for such delicate work. I would try and find someone who has fine soldering skills to do that type of repair.

If you decide to sell send me a PM because it might be something I would be interested in.

Cheers

Could I not just carefully scrap the black paint/material off the connection sitting there (that the pad was connected to) and solder to that?

 

[colostronzos]

Hello i'm new, really interesting thread

I have a Macbook pro 15p Unibody 2009
when i start games every 2 minutes the game slow down for 30sec with a lag of 3 frame per sec, so i cheked the GPU temperature....reach 90-115° Celsius!!!

I open the Mac for clean the fans and i see this, the temperature controller? this is not my photo, my condition is worse! is like burned
is bad?

The fans work correctly and are clean!
What i can do? change the thermal paste for CPU and GPU?


thanks

 

[FuLL]

Image

I think that it's some kind of code that machine knows the right place of the motherboard for smd parts...

Just change thermal paste to cpu and gpu. just check that cooler connects well to gpu and cpu..

i took old thermal paste off from mbp early 2011 and noticed that cooler does not connect at all.. had to put copper shim between gpu and cooler.. ofcourse thermal paste both sides of the copper!

 

[Dadioh]

Could I not just carefully scrap the black paint/material off the connection sitting there (that the pad was connected to) and solder to that?

I don't think so. I believe that was has happened is that the pad itself has completely corroded off the board. Circuit boards are made with layers of copper separated by an insulated material (FR4 is popular). If you dig through the FR4 you will expose the copper below the pad which is not the same signal.

----------

Hello i'm new, really interesting thread

I have a Macbook pro 15p Unibody 2009
when i start games every 2 minutes the game slow down for 30sec with a lag of 3 frame per sec, so i cheked the GPU temperature....reach 90-115° Celsius!!!

I open the Mac for clean the fans and i see this, the temperature controller? this is not my photo, my condition is worse! is like burned
is bad?

The fans work correctly and are clean!
What i can do? change the thermal paste for CPU and GPU?


thanks

Those are test points used in manufacturing to test the logic board. In my experience when they show discoloration like that it usually means a liquid spill has occurred.

The thermal diode for the CPU temperature is built right into the CPU silicon. Th eIntel CPU's will throttle back if they get too hot which is what you are seeing. You need to remove the logic board, remove the heatsink, clean all the old paste, and reapply a good quality thermal compound. Arctic Cooling MX2, MX3, or Ceramique are all good choices.

 

[colostronzos]

I think that it's some kind of code that machine knows the right place of the motherboard for smd parts...

Just change thermal paste to cpu and gpu. just check that cooler connects well to gpu and cpu..

i took old thermal paste off from mbp early 2011 and noticed that cooler does not connect at all.. had to put copper shim between gpu and cooler.. ofcourse thermal paste both sides of the copper!

Thanks!

Those are test points used in manufacturing to test the logic board. In my experience when they show discoloration like that it usually means a liquid spill has occurred.

The thermal diode for the CPU temperature is built right into the CPU silicon. Th eIntel CPU's will throttle back if they get too hot which is what you are seeing. You need to remove the logic board, remove the heatsink, clean all the old paste, and reapply a good quality thermal compound. Arctic Cooling MX2, MX3, or Ceramique are all good choices.

Thanks
My english in bad, you mean that it fell of the liquid on the logic board, i can tell you it never happened, so it is strange i wonder why it is burnished, however, could give me problems?


Yeterday i have tested my Nvidia 9006m GT on OpenGL with same Nvidia demo Heaven banhmark 2 befor on Win7 after that on Osx Muntain Lion, result?
on Win temperatures rise 110°c
on Osx do not arrive at 60 °c after 2h of test 87-95°c
Is trange that on Win themperature rise 115° sometimes and on mac max 87-95°c
it is normal?

I forghet this 20min after start of testing on Osx the temperature ar normal!
.

P.S.
Maybe is a stupid question, but i'm not an expert
The procesor BGA have nothing to do with the high temperatures?
the only thing that BGA have to do with the high temperature is, it may be a broken sphere, but in that case i would not see anything on the screen right?




.

 

[Dadioh]

Thanks!




Thanks
My english in bad, you mean that it fell of the liquid on the logic board, i can tell you it never happened, so it is strange i wonder why it is burnished, however, could give me problems?

.

There was never anything mounted on those points. They are bare test points used in manufacturing so that they can probe those points temporarily as part of the manufacturing testing to make sure the logic board is OK.

When a liquid spill occurs, it often tarnishes or corrodes the surface finish making them discolored. It is often the first warning sign that a board has had a liquid spill.

As far as your other question regarding temperatures, if you are reaching 110C on your CPU there is definitely something wrong. You need to reapply your thermal paste.

 

[colostronzos]

As far as your other question regarding temperatures, if you are reaching 110C on your CPU there is definitely something wrong. You need to reapply your thermal paste.

That's sure, tomorrow i will change thermal paste, i have the Cooler Master E1 is good for my situation?

Anyway i don't know why Win and Osx have this differences of temperature on the same test
you have some hypothesis?

thanks for your help

 

[Mark83]

If another, known good, display does not work then it is your logic board. The 2009 MBP 15" fuse is located on the back side of the logic board. I think there may be some pictures further back in the thread but if you get stuck let me know and I will post a picture of the location.

Hello and thank you for your answer.
The fuse I found and changed, but it doesn't work, the also no backlight.
I red there is a chip named WLED Driver, oder backllight driver.
In the schematic from a 15" mid 2009 I found two of these Driver, you can see it in the attachments.
Have you a idea which one is the right one?

Thx for helping me!

 

[FuLL]

That's sure, tomorrow i will change thermal paste, i have the Cooler Master E1 is good for my situation?

Anyway i don't know why Win and Osx have this differences of temperature on the same test
you have some hypothesis?

thanks for your help

That is very good paste.. use that.

Maybe it's because OSX is better coded and it's not heavy as windows..

 

[Dmitrij77]

Hello!
not full screen backlight
repairs after water

 

[FuLL]

Hello!
not full screen backlight
repairs after water
Image

Had the same problem with MBP 13" early 2011
https://www.dropbox.com/s/5qh0k0cauf2t6sb/Photo 13.3.2013 16.23.23.jpg

Check LVDS connection and if it is same model as i have reflow chip F2117LP

 

[Dadioh]

Hello!
not full screen backlight
repairs after water

The LED's are arranged in 6 strings of LED's that alternate across the bottom of the screen. That pattern indicates that 1 or more strings are not lighting. Since all 6 strings are fed from a single voltage the separation point is the LED return paths. So, somewhere in the return path on the affected LED string there is an open circuit. Either the LVDS connector, zero ohm resistor, or the pin on the backlight driver. Examine these points under magnification.

 

[Maccor]

MacBook Pro early 2008 17inch LED backlight

Hi all. I am in a similar situation to most. I have no backlight but can see the LCD display with a torch shining on the display. I was also able to change the background picture to plain white which makes it easier to see.


Does anyone know is the F9800 fuse the same on my board. I have located it and getting a zero Ω reading on the fuse.

I could take the display off and test it on another machine but I am worried about it damaging another board so would prefer not to.

What I do know is that the backlight display was flickering before it decided to kick the bucket.

Any help would be much appreciated.

If pics are needed I should be able to post them up.

Maccor

 

[FuLL]

Maccor

Sorry but it has CCFL..not LED.

Try changing inverter. if not working then it's most likely one of the tubes..

 

[Maccor]

Sorry but it has CCFL..not LED.

Try changing inverter. if not working then it's most likely one of the tubes..

Are you sure about that?

I have the high res screen which is LED-backlit 1920x1200 according to the specs.

I may not have posted that important part.

 

[Dadioh]

Are you sure about that?

I have the high res screen which is LED-backlit 1920x1200 according to the specs.

I may not have posted that important part.

Yes. I checked everymac.com for specs and there is indeed an available LED backlit option. I have zero experience with that model. Could you post some high res pictures of the circuit board near the LVDS connector. Both front and back and I will see if I can spot it.

 

[fmoras]

Macbook Pro A1278 820-2879-B MID 2010 2.4GHZ

Hello from Greece..

After hours of researching @ internet finally i found this thread and i think that it smells success...

I have a macbook pro unibody 13.3 820-2879-B MID 2010 2.4Ghz. I spilled bacardi with coca cola on it so you understand the story as many people here describes it. I cleaned very carefully the logicboard and when i reconnect it again to the macbook it powers ON!!!!! i was very happy BUT after 20 sec's BOOM!!! backlight off. with a torch classically i can see everything. macbook pro works perfectly but after 2 months i can't see with torch anything, but logicboard works perfectly as i understand. So i attached some pics to see the logicboard. At my experience the problem is on lvds connector on logicboard. In this thread i found the words " WLed Driver " & "fuse" . Please help me to solve my problem to power on my macbook monitor. I found a specialist an he exam the lvds cable an told me that it's ok. I put this logicboard to another same macbook pro to test but the same results. if the problem is to change the L8545SQ or to bridge the fuse please give me instructions .... Thanks in advance !


PS: sorry for my english !

 

[Dadioh]

Hello from Greece..

After hours of researching @ internet finally i found this thread and i think that it smells success...

I have a macbook pro unibody 13.3 820-2879-B MID 2010 2.4Ghz. I spilled bacardi with coca cola on it so you understand the story as many people here describes it. I cleaned very carefully the logicboard and when i reconnect it again to the macbook it powers ON!!!!! i was very happy BUT after 20 sec's BOOM!!! backlight off. with a torch classically i can see everything. macbook pro works perfectly but after 2 months i can't see with torch anything, but logicboard works perfectly as i understand. So i attached some pics to see the logicboard. At my experience the problem is on lvds connector on logicboard. In this thread i found the words " WLed Driver " & "fuse" . Please help me to solve my problem to power on my macbook monitor. I found a specialist an he exam the lvds cable an told me that it's ok. I put this logicboard to another same macbook pro to test but the same results. if the problem is to change the L8545SQ or to bridge the fuse please give me instructions .... Thanks in advance !


PS: sorry for my english !

It looks like the 2 pins on the LVDS connector that carry the backlight voltage are corroded and are probably not carrying the voltage for the backlight. My guess is that you will need to replace the LVDS connector on the logic board. You will need someone with excellent soldering skills to do that.

 

[fmoras]

It looks like the 2 pins on the LVDS connector that carry the backlight voltage are corroded and are probably not carrying the voltage for the backlight. My guess is that you will need to replace the LVDS connector on the logic board. You will need someone with excellent soldering skills to do that.

Thanks. is there any WAY to check that lvds connector fails to send voltage? or i must change the connector to test it. My specialist told me to bridge the pin of lvds cable with pin of lvds connector. Can help this ? or there is no reason to try this.. An wich fuse i have to check if it's blown and with the wled driver how can i understand that is ok ? Thank you again !!

 

[Dadioh]

Thanks. is there any WAY to check that lvds connector fails to send voltage? or i must change the connector to test it. My specialist told me to bridge the pin of lvds cable with pin of lvds connector. Can help this ? or there is no reason to try this.. An wich fuse i have to check if it's blown and with the wled driver how can i understand that is ok ? Thank you again !!

I indicated fuse on attachment. The LVDS pins that carry backlight voltage are pins 21 and 22. Pin 30 is the far left pin in the photo. Count backwards from there.

If the pins are corroded off then you are really just left with replacing the connector. You "could" try bridging solder from the logic board to the stubs on the connector but being corroded the solder probably won't stick and you would likely melt the plastic of the connector.

There is no way to bridge from the logic board to the LVDS cable connector since the pins are hidden once inserted into the connector.

My advice is to focus on obtaining one of the LVDS connectors from eBay and find someone who can replace it.