MacBook Pro Unibody - No Backlight - Logic Board Question

[joenot443]

Thanks very much for the quick reply Dadioh!

This is the correct LVDS cable, yes?

http://r.ebay.com/bb7vQj

Is it possible replacing the cable is all that needs to be done, or should I expect to have to replace the fuse as well?

 

[Jabran]

Help with Fuse/WLED?

Dadioh, I have a Mid-2009 Macbook Pro 2.26Ghz that the backlight is out on, I shorted something I believe because I had the battery in and when I was connecting the cable to the lcd a spark flew out from the gold lock where you push it down to secure the cable in place. I don't know if the fuse is blown, or the WLED chip itself needs to be replaced. I was wondering if you would be able to do it for me? I could ship you my MacBook Pro and you could fix it? I can pay you, however I was thinking something a bit more reasonable because I am a college student and don't have $150 to shell out on a single repair. I'd appreciate a response back or any help at all. Or on the other hand how would I repair this myself? Where would I take it to get it soldered? I have included pictures below to show you the area of the WLED and Fuse, please let me know if it is missing/damaged.

EDIT: Pictures are not showing up, no matter which browser I use, MacRumors is giving me an error. Can I email them to you?

 

[Jabran]

No help?

Thank you so much for the help everyone! I really appreciate the kind responses in solving my issue! Once again, thank you!

 

[lazton]

Logic Board A1278 Issue - Component broken - Does not turning on

Hello together,

I have broken one component on the installing my second HDD.

Do somebody know, which component is missing and what value has this part???

MacBook Pro 13" 2009 Intel 2.26
Logic Board A1278
PART NUMBER: 820-2530

Enclosed is the picture.

Thank you guys in advance,
Anton

 

[U-234]

Need to replace a small inductor.

Hello friends, haven't posted here for few months was busy with the house project. I'm working on A1237 MacBook Air 2008 that has a display issue (black screen, backlight is on) the screen is ok as it was tested with other working LB. I was able to trace it back to these signals LVDS_A_CLK_F_N and LVDS_A_CLK_F_P. The inductor carrying these signals was damaged.
I need to find a replacement for this small inductor, I looked on both Newark and Digikey. It is 1210-4SM1 package with four legs also 90-OHM-100MA. This small inductor looks like it is made up of two small parts glued together. Also I don't know why if it is inductor the inductance should be measured in uH the schematic shows 90ohm like this is impedance?

Ordered tons of stuff from DigiKey for some strange reason can't find this guy....

 

[luchy]

MacBook pro 2011 13' no backlight

Hi! My name is Luca ad i have a big problem with my macbook pro.
i can see the screen but the backlight does not work.
I have already tried to change the screen and the LVDS cable but with no results.
Please how can I proceed?
Thanks in advance

 

[Dadioh]

Hello friends, haven't posted here for few months was busy with the house project. I'm working on A1237 MacBook Air 2008 that has a display issue (black screen, backlight is on) the screen is ok as it was tested with other working LB. I was able to trace it back to these signals LVDS_A_CLK_F_N and LVDS_A_CLK_F_P. The inductor carrying these signals was damaged.
I need to find a replacement for this small inductor, I looked on both Newark and Digikey. It is 1210-4SM1 package with four legs also 90-OHM-100MA. This small inductor looks like it is made up of two small parts glued together. Also I don't know why if it is inductor the inductance should be measured in uH the schematic shows 90ohm like this is impedance?

Ordered tons of stuff from DigiKey for some strange reason can't find this guy....

This is actually a ferrite for control of EMI emissions. They rate them for impedance at a certain frequency. In a pinch you could bypass it to make sure everything works ok. You would just be radiating into the space around you but ok for a quick test.

----------

Hi! My name is Luca ad i have a big problem with my macbook pro.
i can see the screen but the backlight does not work.
I have already tried to change the screen and the LVDS cable but with no results.
Please how can I proceed?
Thanks in advance

First thing to check is the fuse that feeds the backlight driver. The location for many different MacBooks can be found imbedded in this thread. Otherwise post a high res picture of the area near the LVDS connector both front and back and we can locate it for you.

 

[luchy]

Thanks for the quick response.
Yes, I tested the fuse with a multimeter and it is functioning properly.
I read that it could be the WLED driver.
i can test the component?

 

[U-234]

This is actually a ferrite for control of EMI emissions. They rate them for impedance at a certain frequency. In a pinch you could bypass it to make sure everything works ok. You would just be radiating into the space around you but ok for a quick test.

You are absolutely correct this is the part which is rated in impedance. I did the bypass just to test it however I still have no video. The backlight is ok.

Now if you look at my snapshot the issue is with L9006 which is one of 5 identical components. The other four however measure 167KOhms on pins 1 and 2. When I measured pin 1 and 2 of L9006 I was getting only 22Ohms on pin 2 and OL on pin 1, I got the same measurements even when I removed it, actually there was no changes in readings with or without the component. So me getting 22Ohms and OL instead of 167K is a definitely a red flag.

Now, the problem is that....pins 1 and 2 go directly to my NB and this worries me Do you agree that my NB is bad as there is nothing between? If NB is bad it is beyond my repair capabilities

 

[Windc]

Fuse and WLED locations please. Early 2011 15" MacBook Pro 2.2GHz I7

Hi

Like below, similar story except after cracking a screen. Everything was still running Ok except for damaged areas of image. Replaced it (matt HR and bezel etc a pain). Managed to bend the last two pins on LVDS connector and did not realise that at the time. For a while had no image on new screen but cracked one still functional but then that stopped after I had done some swapping to and fro damaging LVDS connector. Bent/straightened pins appeared to create no LED backlight problem, so fitted new LVDS cable but still no image ( except faint one) and slave working throughout - however that seems to indicate the replacement screen itself is OK and rest of laptop.

Have left it for a few months using as a desktop with the slave screen and now want to try and fix.

Any advice on soldering please or links, to attempt DIY? Have purchased a new fine tip iron and a magnifying glass with arms to hold parts. Assume I should check volts as per this thread on fuse, then if that is not problem go for WLED? [Will try and get a good res picture of board to check board level part no but hoping it will be same/similar to marked up one in quote below....]

Great thread and many thanks for getting me this far to diagnose my self inflicted problem.

Windc

Hi all,

Like many in this thread, after an unfortunate liquid spill on my MacBook, I've lost all capabilities of the machine's backlight. The rest of the computer works fine - the image can be displayed on an external monitor and if a light is shone through, the image can be seen on the laptop's screen as well. The only issue lies in the backlight.

It is an early 2011 15' MacBook Pro. I have attached some photos of the affected logic board areas, I have already cleaned them as best I can with rubbing alcohol, unfortunately to no avail.

It appears as if the two leftmost pins on the LVDS connector cable have either been corroded or broken off. Could it be possible this is the issue?

If not, could someone point out the areas on the board I should be testing with a multimeter in order to find the faulty fuse?

Mostly I'm just looking for someone to point me in the right direction.

Thank you very much for your help!
Image

Image

Image

 

[Dadioh]

Hi

Like below, similar story except after cracking a screen. Everything was still running Ok except for damaged areas of image. Replaced it (matt HR and bezel etc a pain). Managed to bend the last two pins on LVDS connector and did not realise that at the time. For a while had no image on new screen but cracked one still functional but then that stopped after I had done some swapping to and fro damaging LVDS connector. Bent/straightened pins appeared to create no LED backlight problem, so fitted new LVDS cable but still no image ( except faint one) and slave working throughout - however that seems to indicate the replacement screen itself is OK and rest of laptop.

Have left it for a few months using as a desktop with the slave screen and now want to try and fix.

Any advice on soldering please or links, to attempt DIY? Have purchased a new fine tip iron and a magnifying glass with arms to hold parts. Assume I should check volts as per this thread on fuse, then if that is not problem go for WLED? [Will try and get a good res picture of board to check board level part no but hoping it will be same/similar to marked up one in quote below....]

Great thread and many thanks for getting me this far to diagnose my self inflicted problem.

Windc

Sounds like you need to replace the lvds connector on the logic board. This requires very fine soldering skills and good magnification. Not sure a magnifying glass will be good enough. I use binocular microscope on high magnification (about 6 pins wide in the viewing window) and that is still tough work getting all pins soldered without bridging any.

 

[Mori3000]

Hello guys

How nice that this nice forum is working again.

I have got a MBP 2011 or 2012 that is liquid damage, as usual no back light.

I have replace the fuse and the LCD back light driver, the LP8550.

I, m sure i have soldered them in the best way but still no light.
what could the problem be?

 

[Dadioh]

How nice that this nice forum is working again.

I have got a MBP 2011 or 2012 that is liquid damage, as usual no back light.

I have replace the fuse and the LCD back light driver, the LP8550.

I, m sure i have soldered them in the best way but still no light.
what could the problem be?

Did the fuse blow again when you tried after replacing the parts? If it did then there is still a short somewhere. If not then you could start by checking the enable signal on the 8550.

 

[Mori3000]

Hello Didioh

Infact the fuse was not blown from bigining and i thought i can replace it to be 100% sure and after the replacement of the fuse and the driver i still have no back light.

The problem is even now when i check up the check point i have only 3.2 v and 3.5 v on the check points and some of the 0 v.

I think i need to have 25 v on one of the check point and 11.5 on some others when i compared it with a working board.

Thanks for your help

 

[Mori3000]

By the way i have tried to replace the LCD and LVDS cable. but i still have the same problem.

 

[Theorba]

I can't turn my Keboard Lighting off

Hi, my Friends!

I can't turn off my Keboard lighting under Lion, and Mavericks.
With SnowLeo 10.6.8 it works well !! (Fresh installs).
What to do?

MBP 8.3 17" QuadCore 2.2 8GB RAM 128SSD 750HD.

SMC and PRAM O.K.

I.e.: Just AppleCare changed my Motherboard (because of GPU malfunction),
but it seams: before and after is the same problem.

Many Thanks for my Helpers!!

 

[anatomij818]

Macbook Pro 13 inc 820-3115-b

I have an early/mid 2013 macbook pro with a liquid spill. I have tried SMC NVRAM reset. Tried to unplug all the possibilities that could lead to this, but the results are the same. When the Magsafe adapter is plugged in the machine turns on, the led turns on , but no sound no video output, the fans start spinning slowly and then reach maximum speed. Does anybody have any ideas what can cause this issue, are there power pads on this model , i cannot find anything related on this model since its 2013.

 

[U-234]

This is actually a ferrite for control of EMI emissions. They rate them for impedance at a certain frequency. In a pinch you could bypass it to make sure everything works ok. You would just be radiating into the space around you but ok for a quick test.

Just wanted to follow up on my question in the post #1534

Dadioh if you read my post do you think my Norhtbridge is bad?

 

[szupie]

Backlight fuse on A1286 mid-2009 15" Macbook Pro

I'm testing the backlight fuse on my A1286 mid-2009 15" Macbook Pro. When I try to measure the resistance between the two sides of the fuse, I get a variable reading that starts anywhere between 300 to 600 kohms and continuously increases to maybe 900 kohms within 10 seconds as I hold the probes on the fuse (I didn't hold down the probes longer to see whether the numbers would stop climbing up since I'm not sure if that would damage the fuse at all). The values also seem to vary depending on how recently I've tested it. If I reverse which probe touches which side of the fuse (black lead on the right and red lead on the left instead of black on left and red on right), I just seem to read an open circuit. Does this mean that the fuse has blown?

 

[Dadioh]

This is actually a ferrite for control of EMI emissions. They rate them for impedance at a certain frequency. In a pinch you could bypass it to make sure everything works ok. You would just be radiating into the space around you but ok for a quick test.

Just wanted to follow up on my question in the post #1534

Dadioh if you read my post do you think my Norhtbridge is bad?

Not really familiar with the pre-unibody (2010) Airs but if you say the signals go straight to Northbridge and the impedance is wrong then that would suggest bad Northbridge.

----------

I'm testing the backlight fuse on my A1286 mid-2009 15" Macbook Pro. When I try to measure the resistance between the two sides of the fuse, I get a variable reading that starts anywhere between 300 to 600 kohms and continuously increases to maybe 900 kohms within 10 seconds as I hold the probes on the fuse (I didn't hold down the probes longer to see whether the numbers would stop climbing up since I'm not sure if that would damage the fuse at all). The values also seem to vary depending on how recently I've tested it. If I reverse which probe touches which side of the fuse (black lead on the right and red lead on the left instead of black on left and red on right), I just seem to read an open circuit. Does this mean that the fuse has blown?

If the fuse is good then you get an immediate 0 ohms (or couple of ohms depending on the quality of your meter). If you see a rising number when reading a resistance value then your meter is charging a capacitor in the circuit. So, yes, your fuse is blown.

 

[jlugo98]

No backlight in 11 2010 a1370 macbook air

Hello, i have a problem, my backlight strip stopped working, maybe it was a short circuit while i was changing the screen! i have read everything about the fuses! My screen still works, but the backlight doesn't turn on!
Could some one tell me which is the fuse to start, im between 2, the one with an N and, the one with a 100

also which is the wled driver?

thanks a lot your help is really appreciated!

 

[Nuclearblue]

Brithness unstable maybe connected to the LED driver?

Hallo everybody,
i am experiencing this strange behaviour from my display on a Macbook pro A1278 (see video below):

http://www.putlocker.com/file/A0A590571A7AE826


The brigthness is randomly going up and down continuously like in a disco and there are no settings or resets (automatic brighness adjustment) who solved the problem.

I took a look at the motherboord and i have found signs of oxidation inside the boxes that i have marked here:



Do you think the problem can be related to the LED driver or i have to look for something else? The same thing happened with a new display

Thanks for your attention

 

[Mori3000]

Hello, i have a problem, my backlight strip stopped working, maybe it was a short circuit while i was changing the screen! i have read everything about the fuses! My screen still works, but the backlight doesn't turn on!
Could some one tell me which is the fuse to start, im between 2, the one with an N and, the one with a 100

also which is the wled driver?

thanks a lot your help is really appreciated!

Hello jlugo98,

The fuse is the one with the N marked, but the driver is on the back side of board.

 

[NewMacUser2014]

Help! No backlight!

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!

 

[carlsson]

MBP15" Mid 2009

No backlight for me either...

Yesterday i tried to remove the DC board, and instead of disassemble the motherboard as you should, I tried to winkle the DC board out...

In the process I decoupled the LVDS cable from the motherboard, but when mounting it all back together again I had no backlight. *sigh*

Tips: Don't do these kind of jobs when you are in a hurry. Obviously a no-brainer, but sometimes you really don't have a brain.

Fuse? Bad connector? I don't know. However, there are some companies found on eBay that repair these faulty boards. My question to the community is: Can you recommend a certain dealer?

I'm located in Sweden, but can of course ship the faulty board to the entire planet.