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MacBook Pro Unibody - No Backlight - Logic Board Question
- Thread starter Dadioh
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Ich hab was für dich vielleicht hilft es dir weiter.
I have something for you. maybe it will help you further.
which is the right chip?
hi guys
I hope I can get a quick bit of help. i did lots of searching and could not come with an answer for my specific issue.
After A LOT of trouble shooting basically I know its my WLED driver that killed my backlight. Wasnt the LCD, the LVDS cable or the fuse, so all that is left is my mind is the WLED driver...but I think I may have bought the wrong one.
I have a 13in Mack book pro, A1278...Processor 2.53ghz Intel Core 2 Duo, 4gb 1067MHz DDR3, NVIDIA GEForce 9400M 256mb, 13in Mid 2009.
The mobo is a 820-2530-A. On the WLED driver it reads LP8543SQ, but I was recommended to buy a L8545SQ.
Here are some pics of my set up, in cluding the new chip I bought and photos of my mobo. http://imgur.com/a/YOlOO
Basically I am wondering if the chip I bought (L8545SQ) would work for this application. I have a friend who is a master solder man and wants to fix up my computer today
Thank you so much!
hi guys
I hope I can get a quick bit of help. i did lots of searching and could not come with an answer for my specific issue.
After A LOT of trouble shooting basically I know its my WLED driver that killed my backlight. Wasnt the LCD, the LVDS cable or the fuse, so all that is left is my mind is the WLED driver...but I think I may have bought the wrong one.
I have a 13in Mack book pro, A1278...Processor 2.53ghz Intel Core 2 Duo, 4gb 1067MHz DDR3, NVIDIA GEForce 9400M 256mb, 13in Mid 2009.
The mobo is a 820-2530-A. On the WLED driver it reads LP8543SQ, but I was recommended to buy a L8545SQ.
Here are some pics of my set up, in cluding the new chip I bought and photos of my mobo. http://imgur.com/a/YOlOO
Basically I am wondering if the chip I bought (L8545SQ) would work for this application. I have a friend who is a master solder man and wants to fix up my computer today
Thank you so much!
Pin 19 and pin 20 are unused on 8543 but are used on 8545. Vsync for example. Not sure how the 8545 will react without those signals implemented correctly on the logic board. Personally I would just get the right part.
Attachments
hmm, good advice, thank you. so the part I mentioned, the LP8543SQ is the correct one? if so I will purchase today and hope to get this darn computer fixed asap.
Yes. The LP8543SQ is the correct part for the late 2009 Macbook Pros.
Yours being a 2.53GHz must be the higher end late 2009 model. 2010 introduced the 2.4GHz and 2.66GHz Core2Duo.
Chip location - A1297
I bought this MacBook knowing it had liquid damage. After cleaning it and replacing the LCD video connector I was to get it working somewhat. Video works fine when using an external monitor and can be seen on the display if you shine a flashlight to it. From the information I've gathered on this thread and elsewhere I need to locate and find a small chip/WLED drive and replace it. I've seen a couple other posts with my board but could not find anything pointing to the exact location of what needs to be checked/replaced. Could someone point me in the right direction?
Top of board
Bottom of board
I bought this MacBook knowing it had liquid damage. After cleaning it and replacing the LCD video connector I was to get it working somewhat. Video works fine when using an external monitor and can be seen on the display if you shine a flashlight to it. From the information I've gathered on this thread and elsewhere I need to locate and find a small chip/WLED drive and replace it. I've seen a couple other posts with my board but could not find anything pointing to the exact location of what needs to be checked/replaced. Could someone point me in the right direction?
Top of board
Bottom of board
See attached. But that doesn't look like the original fuse and from the looks of the solder this has been replaced before. So someone has already been troubleshooting this issue and may not have told you.
Attachments
No video/POST
Hello - I hope someone will help me and put me in the right direction, here it is:
I have Early 2011 A1278 13" logic board which had a liquid damage. The symptoms are no video/POST. The southbrige chip was reballed and I replaced few shorted components but the issue still remains. The megsafe turns green then orange so it appears to be charging the battery.
After I press the power button the fans spins normally but then after 30 second it starts spinning faster all the way to the full speed. The screen remains dark/no video, no beeps when RAM removed.
I already tried the bypass method that Dadioh mentioned in the other post but that didn't make any difference.
So at this point the video issue might point to GPU chip. I know that if during the quick self test (POST) there is an issue let's say with GPU the whole boot process will be put to a hold. But at the same time SMC chip is also responsible for many parts of communication to/from GPU so at this point I really can't tell which one would be a fault here.
Is there a better way to determine if this is GPU or SMC issue?. I know there are some slot testers to check the communication between GPU but I don't have such device and never used it.
Many thanks to Dadioh for staring this thread!
Hello - I hope someone will help me and put me in the right direction, here it is:
I have Early 2011 A1278 13" logic board which had a liquid damage. The symptoms are no video/POST. The southbrige chip was reballed and I replaced few shorted components but the issue still remains. The megsafe turns green then orange so it appears to be charging the battery.
After I press the power button the fans spins normally but then after 30 second it starts spinning faster all the way to the full speed. The screen remains dark/no video, no beeps when RAM removed.
I already tried the bypass method that Dadioh mentioned in the other post but that didn't make any difference.
So at this point the video issue might point to GPU chip. I know that if during the quick self test (POST) there is an issue let's say with GPU the whole boot process will be put to a hold. But at the same time SMC chip is also responsible for many parts of communication to/from GPU so at this point I really can't tell which one would be a fault here.
Is there a better way to determine if this is GPU or SMC issue?. I know there are some slot testers to check the communication between GPU but I don't have such device and never used it.
Many thanks to Dadioh for staring this thread!
do you know if there is any difference between the LP8543SQ and LP8543SQE?
digikey only has the SQE in stock, not sure if it will work or not.
link for the parts...
http://www.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=LP8543SQ
Thank you again!
Hey, thanks mate for the bv, but as you can see I already used that to locate the components
Anyways:
Does someone have a full datasheet of the LP8550? (not the product brief from TI!).
17" A1297 MacBook Pro with USB & touchpad dead
I just went through this thread and found a lot of helpful info. I'm working on a 17" Macbook Pro a1297 that had a bad lvds connector. It had a short on it.
I replaced the lvds connector and cable. The fuse was also replaced. Before the repair I was able to turn the laptop on with external video and the usb ports and touchpad worked.
Now after I replaced the lvds connector/cable and replaced the fuse the laptop loads up just fine and the main display works but the usb ports and touch pad stopped working.
If anyone can help out I would appreciate it a lot. I have a screenshot of the lvds area.
thanks
I just went through this thread and found a lot of helpful info. I'm working on a 17" Macbook Pro a1297 that had a bad lvds connector. It had a short on it.
I replaced the lvds connector and cable. The fuse was also replaced. Before the repair I was able to turn the laptop on with external video and the usb ports and touchpad worked.
Now after I replaced the lvds connector/cable and replaced the fuse the laptop loads up just fine and the main display works but the usb ports and touch pad stopped working.
If anyone can help out I would appreciate it a lot. I have a screenshot of the lvds area.
thanks
Attachments
Dadioh, I registered just so I could let you know how grateful I am. I fixed my daughter's macbook thanks to you.
Keep up the good work, eh?
Mike Williams
You are welcome eh?
Mid 2010 A1286 Logic Board / no backlight
Hi,
I have broken 15 mid-2010 A1286 Mac book pro that was given to me from a friend. It has liquid damage from a Coke that was spilled on it around a year and half ago. The screen back light use to work but was very dim and some times flicker until it gave up altogether.
I gave the logic board a clean with a tooth brush and IPA to remove the residue from the spilt drink. The back light still dose not work but the LCD works and all other systems are working fine.
Tested the fuse here for continuity with a multimeter and it's a closed circuit.
I believe the WLED driver may be blown, but I don't know where its located and how to test if its working, can you please guide me?
The socket and head for the monitor LVD cable seem to be corroded on some of its pins could this be a possible cause of the problem?
Here are some photos, please forgive the bad quality did it with a phone camera and 2x handheld magnifying scope.
Logic Board Back
Logic Board Front
Area Near LVD socket/spill area
LVD socket
LVD Head Top
LVD Head Bottom
Thanks.
Sorry if someone has already posted the same problem.
Hi,
I have broken 15 mid-2010 A1286 Mac book pro that was given to me from a friend. It has liquid damage from a Coke that was spilled on it around a year and half ago. The screen back light use to work but was very dim and some times flicker until it gave up altogether.
I gave the logic board a clean with a tooth brush and IPA to remove the residue from the spilt drink. The back light still dose not work but the LCD works and all other systems are working fine.
Tested the fuse here for continuity with a multimeter and it's a closed circuit.
I believe the WLED driver may be blown, but I don't know where its located and how to test if its working, can you please guide me?
The socket and head for the monitor LVD cable seem to be corroded on some of its pins could this be a possible cause of the problem?
Here are some photos, please forgive the bad quality did it with a phone camera and 2x handheld magnifying scope.
Logic Board Back
Logic Board Front
Area Near LVD socket/spill area
LVD socket
LVD Head Top
LVD Head Bottom
Thanks.Sorry if someone has already posted the same problem.
No Backlight on Macbook air, 11 inches model A1370, 2011.
I replaced the lcd of my macbook and now the backlight does not work. I did a lot of test according to the schematics by soldering wires to the relevant pins...
you can see the picture below.
Here is my observations:
-- The output voltage of the driver (LP8550) is not boosted at it should (22v). The output that I measure is the same as input (8.4v).
-- PWM signal was before ok, starting from 2.5V and increase with light keys but now I don't get any voltage...
-- The enable signal (EN) coming from the micro controller is 0 all the time instead of logical 1. When I measure the resistance of this pin, it is 30ohm which is kind of grounded...
-- According to the boost circuit, when the enable (EN) of LP8550 is provided, it should start switching to boost the voltage (the switch (SW) is between the inductor and the diode) But I don't see any switching...
-- The fuse was broken which i replaced. Still no backlight.
Dadioh do you have any idea?
Thank you
any help would be highly appreciated.
I replaced the lcd of my macbook and now the backlight does not work. I did a lot of test according to the schematics by soldering wires to the relevant pins...
you can see the picture below.
Here is my observations:
-- The output voltage of the driver (LP8550) is not boosted at it should (22v). The output that I measure is the same as input (8.4v).
-- PWM signal was before ok, starting from 2.5V and increase with light keys but now I don't get any voltage...
-- The enable signal (EN) coming from the micro controller is 0 all the time instead of logical 1. When I measure the resistance of this pin, it is 30ohm which is kind of grounded...
-- According to the boost circuit, when the enable (EN) of LP8550 is provided, it should start switching to boost the voltage (the switch (SW) is between the inductor and the diode) But I don't see any switching...
-- The fuse was broken which i replaced. Still no backlight.
Dadioh do you have any idea?
Thank you
any help would be highly appreciated.
Attachments
I replaced the lcd of my macbook and now the backlight does not work. I did a lot of test according to the schematics by soldering wires to the relevant pins...
you can see the picture below.
Here is my observations:
-- The output voltage of the driver (LP8550) is not boosted at it should (22v). The output that I measure is the same as input (8.4v).
-- PWM signal was before ok, starting from 2.5V and increase with light keys but now I don't get any voltage...
-- The enable signal (EN) coming from the micro controller is 0 all the time instead of logical 1. When I measure the resistance of this pin, it is 30ohm which is kind of grounded...
-- According to the boost circuit, when the enable (EN) of LP8550 is provided, it should start switching to boost the voltage (the switch (SW) is between the inductor and the diode) But I don't see any switching...
-- The fuse was broken which i replaced. Still no backlight.
Dadioh do you have any idea?
Thank you
any help would be highly appreciated.
How do you measure the switching? Did you use a scope or a dmm?
Hi
Yes I used a scope, I expect to see a switching to the ground and back to normal voltage, but there is no switch, It is always a constant voltage (around 8v).
Has anyone here used the solder rework station T862 for replacing BGA packages? I have quite a few boards that I believe the SMC is bad and wanted to be able to replace BGA packages. Sample listing below... there are lot's of them for sale on eBay from various sources for a little over $200.
Wanted to get first hand experience from someone that may have used one on their MacBook logic boards. Thanks.
http://www.ebay.ca/itm/PRO-T862-BGA...RDA-WELDER-SOLDERING-MACHINE-g1-/130620054775
Wanted to get first hand experience from someone that may have used one on their MacBook logic boards. Thanks.
http://www.ebay.ca/itm/PRO-T862-BGA...RDA-WELDER-SOLDERING-MACHINE-g1-/130620054775
Thanks for your reply symuncez :beer:
Schematics are (in most cases) hard to hunt. You need to dig deeply. Especially with these annoying 1000pgs offering to buy that sch. Thank god Google is helping with Chinese/Russian/Polish/... translation.
For component tracking and diagnostic you need at least basic electronic knowledge (caps, resistors, mosfets, power ics, etc.) It gets harder and time consuming when you work with smd and non-labeled cmpnts on the boards. Then you need to search them on board view, if you have it of course (its harder to find than schematic). :banghead:
But after many, many years in troubleshooting you are starting to feel the things. And its more easy when customer is honest when you ask him "What happened before it died?" question.
But in cases like this something simple can lead you to deep .... issues.
Hopefully someone will come out with tough about this one.
Thanks guys, great community is concentrated here.
Hello Zixu
I have followed with interest the problem treated by you.
I have a MBP A1286, 820-2533 A with the same symptoms. Now I have your problem solving can not track.
Question: What is the result?
many greetings
dieett
mistake
Hi all,
I broke my screen but then i changed it this evening and like many people here no backlight... LVDS cable is new as well. I tried to play with the connector while the computer was running, huge mistake i think because after few seconds there were not even picture... i tried to short circuit the capacitor (or fuse?) but it didnt work. what i could hurt while playing with the connector? Apparently its too low voltage to burn any component? What can i check?
Thanks
Dadioh any idea?
I didnt feel the need to post a picture, but i can if needed
Hi all,
I broke my screen but then i changed it this evening and like many people here no backlight... LVDS cable is new as well. I tried to play with the connector while the computer was running, huge mistake i think because after few seconds there were not even picture... i tried to short circuit the capacitor (or fuse?) but it didnt work. what i could hurt while playing with the connector? Apparently its too low voltage to burn any component? What can i check?
Thanks
Dadioh any idea?
I didnt feel the need to post a picture, but i can if needed
Hi all,
I broke my screen but then i changed it this evening and like many people here no backlight... LVDS cable is new as well. I tried to play with the connector while the computer was running, huge mistake i think because after few seconds there were not even picture... i tried to short circuit the capacitor (or fuse?) but it didnt work. what i could hurt while playing with the connector? Apparently its too low voltage to burn any component? What can i check?
Thanks
Dadioh any idea?
I didnt feel the need to post a picture, but i can if needed
The connection pins on the LVDS cable are very close together so if you were playing with it and angled it slightly to the side then you could short adjacent pins. Could have fried the 3.3V supply to the LCD display. Or other possibilities.... Have a look at the LVDS pinout and try to see what the possibilities are. Then check them on the logic board. For example, start with the 3.3V supply.