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MacBook Pro Unibody - No Backlight - Logic Board Question

Dadioh said:
Those last three pins are the backlight pins so at a minimum you need to replace the LVDS cable. You also need to look inside the LVDS connector because it is possible that the interior pins are also corroded or plastic melted in that corresponding connection.

The fuse is identified in my attachment. That is likely blown.
Click to expand...

Hi Dadioh,

Today I replaced the LVDS connector. The repair was successful, however it did not solve the problem. The computer still boots without a backlight.

I am expecting I now need to look into replacing the fuse.

Can you identify the part number I should be looking for? I haven't been able to find it in Google.

Thank you very much for your help!
 
Brightness intensity flickering

Hi Dadioh

after a liquid spill and cleaning a Macbook pro A1278 the back light goes on but
the brigthness is randomly going up and down continuously there are no settings or resets (automatic brighness adjustment) who solved the problem.

I have tried with another perfectly working display assembly and a new LDVS cable but nothing changed.

I am almost sure it is a problem on the circuit who supply voltage to the back light which is unstable.

Could you help me to figure out where i have to check voltages or resistences to solve this issue?



Download video here: http://www.putlocker.com/file/A0A590571A7AE826

Thanks for your great post here!
 
Mid-2009 A1268 Macbook Pro 2.66GHz

I have no video on my Mid-2009 A1268 Macbook Pro 2.66GHz I have checked all the fuses and they are all ok to the best of my knowledge, I did bot a continuity test and measured the resistance of the backlight fuse and both are good. When I bought this machine it had water damage and pretty severe corrosion at U7100 ( ISL9504 ) I cleaned all the contacts around it and re-flowed the QFN package just to make sure everything was making contact. I still have no video.

Also PIN 3 of the LVDS Connector ( PPVOUT_S0_LCDBKLT ) was burnt right out I have replaced both the connector and the cable. Only one side of the connector had damage so I don't believe that the power surge went all the way to the LED screen but I do not have another to test against so I am not sure weather it did or not.

Does anyone know of a way to test the U7100 to see if that is bad or not and the LVDS to make sure it is getting the voltages it needs on the right pins.

I attached a couple of pictures of the original damage to show what I was up against. Any help from anyone would be awesome, I love the challenge of trying to get these things back to life but this one has me stumped.

Thanks in advance for any help I know someone on here can get me threw this I have read the whole thread and there is some talented people on here for sure.

Forgot board number is 820-2523-B
 

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Forgot to mention

Sorry I also forgot to mention in my post above that there is also damage to the iSight connector as well. And I cleaned that up and when I plugged it back in one of the resistors or capacitors burned right up. Not sure which it was I didn't notice what it was before I watched it burn up.

The iSight being messed up wouldn't mess with the screen now working would it? I wouldn't think so but you never know I guess. Thanks again for any help anyone can provide I can't wait to make this thing live again.
 
NewMacUser2014 said:
I recently had a working but cracked screen. After switching out the screen it now has no backlight! I tried switching back to old screen amd no dice so it looks like i am plagued with this issue. It is a late 2008 a1286 2.8ghz.

I tried the sodering my skill level on a scale of 1-10 is .5 - is there anyone in the nyc area that can help out? Thanks!
Click to expand...

Hi! Anyone in the area? Thanks!
 
This interesting thread has caused me to step out and attempt repair on my 2010 MacBook with a damaged lvds connector and backlight fuse. I have nothing to lose, and in the process of an accounting degree, I suppose a little electrical engineering education isn't bad, ha.

I have a little soldering experience, but does apples solder have a different melting point, do they use glue too, or what? I am having a tough time with removal. Even with heat. What temperature do you guys use on your rework stations to remove them? I borrowed one from a friend (an aoyue?) and don't want to get too impatient, get it too hot, and ruin my chance of repair instantly. I have the right tools (his metcal soldering station too) but I thought I would get some of you guys opinions/techniques before I get too aggressive with this removal. His pinball machine repair experience isn't too helpful!!
 
Kmad86 said:
This interesting thread has caused me to step out and attempt repair on my 2010 MacBook with a damaged lvds connector and backlight fuse. I have nothing to lose, and in the process of an accounting degree, I suppose a little electrical engineering education isn't bad, ha.

I have a little soldering experience, but does apples solder have a different melting point, do they use glue too, or what? I am having a tough time with removal. Even with heat. What temperature do you guys use on your rework stations to remove them? I borrowed one from a friend (an aoyue?) and don't want to get too impatient, get it too hot, and ruin my chance of repair instantly. I have the right tools (his metcal soldering station too) but I thought I would get some of you guys opinions/techniques before I get too aggressive with this removal. His pinball machine repair experience isn't too helpful!!
Click to expand...


The reason it seems hard to remove components is, Apple logic boards have many layers so there is more going on than meets the eye. Because of this the board will soak up the heat. I pre-heat by keeping the heat gun 3-4 inches away and heat the general area at 200C then when I move in I bump it up to around anywhere from 310C to 360C depending on the size of the package I am working on.

You are correct not to get to anxious. Soldering and this type of stuff takes time and patience for sure. God luck there are a couple of videos on youtube but most people there don't tell you what temps they are using.

Also I have the same kind of machine you are using and I had to calibrate the degree setting on it. Maybe that way you problem all along.
 
tswartfiguer said:
The reason it seems hard to remove components is, Apple logic boards have many layers so there is more going on than meets the eye. Because of this the board will soak up the heat. I pre-heat by keeping the heat gun 3-4 inches away and heat the general area at 200C then when I move in I bump it up to around anywhere from 310C to 360C depending on the size of the package I am working on.

You are correct not to get to anxious. Soldering and this type of stuff takes time and patience for sure. God luck there are a couple of videos on youtube but most people there don't tell you what temps they are using.

Also I have the same kind of machine you are using and I had to calibrate the degree setting on it. Maybe that way you problem all along.
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I don't have his manual for the station. How do you calibrate the setting? Use a thermocouple and multimeter for accurate temperature?
 
Kmad86 said:
I don't have his manual for the station. How do you calibrate the setting? Use a thermocouple and multimeter for accurate temperature?
Click to expand...

What is the model of the soldering/rework station you have I will look for the manual for you.

But yes you use a external method of measuring the temperature output of the machine so you can make your adjustments to the machine.
 
tswartfiguer said:
What is the model of the soldering/rework station you have I will look for the manual for you.

But yes you use a external method of measuring the temperature output of the machine so you can make your adjustments to the machine.
Click to expand...

It's the 968A+ Their website doesn't seem too in-depth.
 
Hi !

I have a similar situation, an A1286 mbp with severe water damage.
I am repairing components one by one, but to do a better job i need the boardview file.

Does by chance someone got the file K91X_MLB_DVT .brd and is willing to share ?

thanks !
Dave
 
laptopmd said:
Hi !

I have a similar situation, an A1286 mbp with severe water damage.
I am repairing components one by one, but to do a better job i need the boardview file.

Does by chance someone got the file K91X_MLB_DVT .brd and is willing to share ?

thanks !
Dave
Click to expand...

I might have it what is the board number? It should look like 820-XXXX with a revision letter after the numbers.
 
820-2936-B find inverter, BGA or WED driver fault

Hello,
Great Forum. I have a 2011 MBP 13" logic board 820-2936-B with a black screen. The system will post and display is good on external monitor. In the Video connector area A small resistor/capacitor was missing two components had a damaged foot. KNP Y3 AND S8, lastly the video connector was damaged slightly. using a IR rework system I replaced the connector and three components. All fuses are tested good. I am still getting the same issue. Black screen but working with an external monitor. I would love direction to the video circuit on the logic board? or pictures showing proper voltage points or resistance measures?
Is there a typical failure?
Thanks in advance.
 
Sheridansystems said:
Hello,
Great Forum. I have a 2011 MBP 13" logic board 820-2936-B with a black screen. The system will post and display is good on external monitor. In the Video connector area A small resistor/capacitor was missing two components had a damaged foot. KNP Y3 AND S8, lastly the video connector was damaged slightly. using a IR rework system I replaced the connector and three components. All fuses are tested good. I am still getting the same issue. Black screen but working with an external monitor. I would love direction to the video circuit on the logic board? or pictures showing proper voltage points or resistance measures?
Is there a typical failure?
Thanks in advance.
Click to expand...

Hi Sheridan, i had a similar problem and it was only the voltage missing on the Backlight pin.

There must be a fuse on this line, that sometimes burn, especially if water damage.

Unfortunately i don't have the schematics here now, to tell you exactly which part to check...

Dave
 
Early 2011 MBP 15 Won't Power On

Hi everyone, after a lot of searching regarding my issue I decided to reach out and ask and hope someone can help me. Sorry that I post it in here since I know this thread is about water damage, but seems that is where I have the best chance of getting help. After a lot of testing Im still in the same place and haven't come out with a solution. The only thing I have noticed is that one capacitor is broken (doesn't seem burned out). Also there is a controller next to the same capacitor that when the magsafe is plugged in it gets really hot (won't happen when using battery only). Another symptom is that when pressing the power button (this time on battery) the same controller gets hot for about 3 seconds and then gets cold again(nothing comes on) and if I do a SMC reset the fans will turn on high speed(just the fans,no video,chime or hard drive activity) and the same controller will get hot again but these time stays hot. I really appreciate any help on the matter. Im desperate :eek:
Regards,
Tito
 

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l0l0pr said:
Hi everyone, after a lot of searching regarding my issue I decided to reach out and ask and hope someone can help me. Sorry that I post it in here since I know this thread is about water damage, but seems that is where I have the best chance of getting help. After a lot of testing Im still in the same place and haven't come out with a solution. The only thing I have noticed is that one capacitor is broken (doesn't seem burned out). Also there is a controller next to the same capacitor that when the magsafe is plugged in it gets really hot (won't happen when using battery only). Another symptom is that when pressing the power button (this time on battery) the same controller gets hot for about 3 seconds and then gets cold again(nothing comes on) and if I do a SMC reset the fans will turn on high speed(just the fans,no video,chime or hard drive activity) and the same controller will get hot again but these time stays hot. I really appreciate any help on the matter. Im desperate :eek:
Regards,
Tito
Click to expand...

If you have the schematic for the board check and see what pin the capacitor is hooked to on the QFC package there. You can count the pins by looking for a dot on the chip and count counter-clockwise to find what pin it is. The schematic should tell you what line has been disrupted and that will hopefully tell you or someone here more about what is going on.

Do you get the green magsafe light what you plug the charger in and if you do does it turn amber indication that it is charging the battery?

Also find the board number it looks like 820-XXXX that way maybe someone has the schematic and can tell you what line it is and what capacitor is blown.
 
tswartfiguer said:
If you have the schematic for the board check and see what pin the capacitor is hooked to on the QFC package there. You can count the pins by looking for a dot on the chip and count counter-clockwise to find what pin it is. The schematic should tell you what line has been disrupted and that will hopefully tell you or someone here more about what is going on.

Do you get the green magsafe light what you plug the charger in and if you do does it turn amber indication that it is charging the battery?

Also find the board number it looks like 820-XXXX that way maybe someone has the schematic and can tell you what line it is and what capacitor is blown.
Click to expand...

I don't have the schematic and thanks for the info regarding on how to find the pin linked to the capacitor . Yes the Magsafe light tuns green when it is first connected then turns amber (at least that seems to work) :D. LB model 820-2915-B
 
l0l0pr said:
I did look for it but was not able to find it. I want to thank you for finding the schematic and the taking of your time. I really appreciate it!
Regards,
Tito
Click to expand...

Post a full view photo and circle the chip so we can see the location of it I might be able to identify it for you. And your welcome, thats what this forum is for.
 
tswartfiguer said:
Post a full view photo and circle the chip so we can see the location of it I might be able to identify it for you. And your welcome, thats what this forum is for.
Click to expand...
I might be wrong but I think the schematic is for the 2010 MBP (820-2936/A) and not for the 2011 MBP (820-2936-B) correct me if I'm wrong.
 

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l0l0pr said:
I might be wrong but I think the schematic is for the 2010 MBP (820-2936/A) and not for the 2011 MBP (820-2936-B) correct me if I'm wrong.
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You are right the schematic I pointed out is for the 13" MBP you have a 15.4" on right?

----------
tswartfiguer said:
You are right the schematic I pointed out is for the 13" MBP you have a 15.4" on right?
Click to expand...

I have the same board number and I have the 13" model its a 2011 MBP with the board number 820-2936-B. Thats why I told you you needed this schematic but that is weird there has to be a different drawing for the 15.4" model. I will dig around today and see what I can find. Sorry about that.
 
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