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Hi Guys,

did everyone has the schematic for the non-pro a1278 13.3"? I need them to check the WLED driver. The fuse isn't broken. The Display Cable and the Display works. I don't know the position of the WLED driver and the right configurations.

I can't find anything about them on this Thread.
Please sent me an Link or anything.

I need really help!

Is this what you are looking for? I have the same MB as you and am waiting to see if mine is the WLED driver as well. My screen was originally shattered, ordered a new one, and replaced with no BL.

Sounds like this qaiser57 guy had the same laptop/board as us and was told that the only way to purchase a replacement WLED is off a faulty board as non-pro model used proprietary parts. :(

Check out posts 162-168 here and let me know if I am wrong in my thinking please.

Anyone else with the non-Pro 13" unibody find a place to pick up a spare WLED? TIA
 
Last edited:
Dadioh: I don't have an operating system installed. As I've stated in my post #640 I don't have a working screen to install OS X. If I understand the Command-F1 correctly it works only if you have OS X installed and a up and running Mac. I not at that point yet. Thank you for your reply.

In the process of reviving a liquid spill Macbook A1342 2.26mhz I would like to know if the Mini Displayport can be used in lieu of the internal display. My screen and cable are unknows as a result of the liquid spill. If someone knows how to use the Mini Displayport, considering the condition of my Macbook, please explain it to me. Your help would be very much appreciated. Thank you.

Yes. You can use an external display on the mini-DP. I have 2 MacBooks that I use as media centres that have no internal display connection. I just run a min-DP to HDMI adapter and use the TV as the display. I removed the screen from the Macbook so it is not in the way since it is not being used anyway.
 
hey DAdioh

On the 13 MBP it is actually on the other side of the board from the CPU and GPU which makes it very convenient to check. It is a 2A fuse in an 0402 package so it is tiny. Fortunately I have a stereo microscope that I use for soldering :)


Im have the same problem, i found out the backlight fuse was not working. Its pretty small. Found this picture on the web that shows the exact fuse.
https://forums.macrumors.com/attachment.php?attachmentid=301342&d=1314998993

i been told to just bridge the fuse but i don't have a good feeling about it. This fuse is pretty small, i want to replace it myself. What tools do i need, for example soldering iron or hot air rework. Im fairly new to soldering and i want to practice before doing such work. Any tip/ help
 
Im have the same problem, i found out the backlight fuse was not working. Its pretty small. Found this picture on the web that shows the exact fuse.
https://forums.macrumors.com/attachment.php?attachmentid=301342&d=1314998993

i been told to just bridge the fuse but i don't have a good feeling about it. This fuse is pretty small, i want to replace it myself. What tools do i need, for example soldering iron or hot air rework. Im fairly new to soldering and i want to practice before doing such work. Any tip/ help

Bridging is not really a good idea. The fuse blew for a reason. That reason may have been temporary (like liquid hitting the circuit) but it is also possible that the condition still exists (like a short internal to the WLED driver for example). Bridging the fuse if the fault condition still exists WILL release the smoke and you are now faced with much more than just a fuse replacement.

If the reason the fuse blew was a liquid spill then carefully clean the area around the WLED driver (front and back of board) and if possible, examine closely with magnification to determine if there is residue or obvious corrosion. Clean with 99% pure isopropyl alcohol and a toothbrush.

If you want to be careful before replacing fuse you could check the resistance on all of the WLED pins to ground to see if there is a problem. There is a chart of typical values earlier in the thread.

Another common fault that causes fuse to blow are shorts inside the LVDS connector. Check the resistance between the backlight voltage pins on the connector to ground. Sometimes there is an internal short. Sometimes possible to straighten the pins under heavy magnification but connector replacement is most likely going to be the solution.

The soldering method I use for replacing the fuse is:

1) Using 2 fine tip soldering irons, one on each end of the fuse, and lift the fuse off. Kind of like hot tweezers.
2) Clean the solder pads on the board removing any large quantity of solder left behind.
3) Apply solder flux to the pads.
4) Under magnification, place the new fuse on the pads and hold down the centre of the fuse with fine tip tweezers.
5) With one soldering iron apply solder to one end of the fuse.
6) Remove tweezers and move to other end of fuse and apply solder. Touch up as required.

Caution needs to be exercised to not apply too much heat for too long. Fuses are thermal devices by nature and you can end up blowing the fuse just by too much heat in the soldering process.

As far as the tools the primary concern is a decent soldering iron and a very fine tip. I use a Metcal SP-200
with a tip something like the SSC-726A tip shown on the page. I use a 700 series (temperature) tip.

I personally don't see how you can do it without magnification but some people seem to achieve this. Binocular microscope is ideal.

Good luck with the repair :)
 
Can I just ask the Apple Store employees to solder the fuse? It seems harder to do it myself.
 
Is this what you are looking for? I have the same MB as you and am waiting to see if mine is the WLED driver as well. My screen was originally shattered, ordered a new one, and replaced with no BL.

Sounds like this qaiser57 guy had the same laptop/board as us and was told that the only way to purchase a replacement WLED is off a faulty board as non-pro model used proprietary parts. :(

Check out posts 162-168 here and let me know if I am wrong in my thinking please.

Anyone else with the non-Pro 13" unibody find a place to pick up a spare WLED? TIA


ok... i checked this pin and i had only 0,00V.

what do you mean?
 
ok... i checked this pin and i had only 0,00V.

what do you mean?

The boost diode indicates the voltage that drives the backlight LED's. When the backlight is on it should be somewhere around 24V to 27V. Since you are measuring 0V this just indicates you have no backlight and will require further trouble shooting to determine the cause.
 
Bridging is not really a good idea. The fuse blew for a reason. That reason may have been temporary (like liquid hitting the circuit) but it is also possible that the condition still exists (like a short internal to the WLED driver for example). Bridging the fuse if the fault condition still exists WILL release the smoke and you are now faced with much more than just a fuse replacement.

If the reason the fuse blew was a liquid spill then carefully clean the area around the WLED driver (front and back of board) and if possible, examine closely with magnification to determine if there is residue or obvious corrosion. Clean with 99% pure isopropyl alcohol and a toothbrush.

If you want to be careful before replacing fuse you could check the resistance on all of the WLED pins to ground to see if there is a problem. There is a chart of typical values earlier in the thread.

Another common fault that causes fuse to blow are shorts inside the LVDS connector. Check the resistance between the backlight voltage pins on the connector to ground. Sometimes there is an internal short. Sometimes possible to straighten the pins under heavy magnification but connector replacement is most likely going to be the solution.

The soldering method I use for replacing the fuse is:

1) Using 2 fine tip soldering irons, one on each end of the fuse, and lift the fuse off. Kind of like hot tweezers.
2) Clean the solder pads on the board removing any large quantity of solder left behind.
3) Apply solder flux to the pads.
4) Under magnification, place the new fuse on the pads and hold down the centre of the fuse with fine tip tweezers.
5) With one soldering iron apply solder to one end of the fuse.
6) Remove tweezers and move to other end of fuse and apply solder. Touch up as required.

Caution needs to be exercised to not apply too much heat for too long. Fuses are thermal devices by nature and you can end up blowing the fuse just by too much heat in the soldering process.

As far as the tools the primary concern is a decent soldering iron and a very fine tip. I use a Metcal SP-200
with a tip something like the SSC-726A tip shown on the page. I use a 700 series (temperature) tip.

I personally don't see how you can do it without magnification but some people seem to achieve this. Binocular microscope is ideal.

Good luck with the repair :)


Thank you Dadioh for the quick reply. One last question, which would you recommend?

http://www.amazon.com/X-TRONIC-MODE...ref=sr_1_3?s=hi&ie=UTF8&qid=1338770333&sr=1-3

or the metcal sp200
 
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Thank you Dadioh for the quick reply. One last question, which would you recommend?

http://www.amazon.com/X-TRONIC-MODE...ref=sr_1_3?s=hi&ie=UTF8&qid=1338770333&sr=1-3

or the metcal sp200

I did the repair with a $20 soldering iron (but if you have the money, which I don't, go right ahead! A good iron is the main tool of geeks everywhere!)

Or you could find someone locally willing to lend an iron- geeks usually are :D

But as Dadioh said, do NOT bridge the fuse. I thought about doing it, but my LDVS pin was bent out of whack and blew it again. If I bridged it, it wouldve died...
 
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Thank you Dadioh for the quick reply. One last question, which would you recommend?

http://www.amazon.com/X-TRONIC-MODE...ref=sr_1_3?s=hi&ie=UTF8&qid=1338770333&sr=1-3

or the metcal sp200

Looks like a Hakko knock-off. It would probably do fine for what you are doing particularly if soldering will be an infrequent job. The SP200 is an excellent iron but they aren't cheap. You might be able to find a good deal on a used one on eBay but, as I said, the one you linked would work. Just make sure you get a very fine tip for it.
 
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Originally Posted by Sold View Post
Hello.
PLEASE Dadioh help me with a answare for 612 post...

i have only light...no image on monitor...even on external don-t image apear after someoane put e defective display...

A rule of thumb, I imagine I posted earlier in this thread.

a) No backlight, but image - motherboard problem.

b) No backlight, no image - LCD problem. OR, GPU problem on board. 90% chance LCD, 10% chance GPU, on Unibody models.

c) Backlight, no image - LVDS cable problem.

I would suggest replacing the LVDS cable.
 
astroboy907

I managed to repair my fuse using a $20 soldering iron and a $6 tips package. I use a MAKE: branded iron, its on their website. Got it as a gift.

That, coupled with magnification and a friend holding a flashlight, a pair of tweezers, and some 91% alcohol, it turned out fine.

Basically, if it works right now, and you got the fuse off, you did the hardest part. It took me ~1 hour to remove the fuse, and 5 minutes to get it back on. If you arent willing to spend much money on it, look for someone local...

----------




It sound like a logic board problem, IMO. If it doesnt show an image on an external display, something is wrong with the board.

If it works with one screen but not with another, leave the screen that works on...

The vertical stripes are usually caused by one of the LED return lines being loose in the connector. Make sure the connector is in ALL the way, and that there are no pins folded onto the back of the connector. Use magnification to check if the connector is alright.


i use for test original deffective display with stripes and i have a new one...the same show only white display like a paper !!!

someoane say i must rewrite nvram becose he think it-s reseted...

with no image windows loads...

internal display-only light lika a paper...external display...no image...
 
i use for test original deffective display with stripes and i have a new one...the same show only white display like a paper !!!

someoane say i must rewrite nvram becose he think it-s reseted...

with no image windows loads...

internal display-only light lika a paper...external display...no image...

Are you using te same LDVS cable for both displays? What do you mean windows loads on it?

Is there anything on an external display when running Mac?

If there is no image on external display, running mac, try resetting SMC. If that doesnt fix it, it might be the logic board. :(
 
Sorry this is not relevant to the backlight issues however I urgently need your help on a customers A1181.
These Mac's had the feature of automatic power on after power is lost. Hence the laptop powered on and everything works, except for me not knowing the power button itself is not working. I powered it down from the Apple drop down menu now cannot get it to boot AT ALL. I've touched the power pads on the board together, even the 1st and 4th pin in the keyboard connector but no life. What should I do?

Its the high end 2.4GHZ A1181. Thank you !!
This is urgent.
 
Sorry this is not relevant to the backlight issues however I urgently need your help on a customers A1181.
These Mac's had the feature of automatic power on after power is lost. Hence the laptop powered on and everything works, except for me not knowing the power button itself is not working. I powered it down from the Apple drop down menu now cannot get it to boot AT ALL. I've touched the power pads on the board together, even the 1st and 4th pin in the keyboard connector but no life. What should I do?

Its the high end 2.4GHZ A1181. Thank you !!
This is urgent.

I believe if you unplug the bios battery & put power on the board it will power up without power button.The older A1181's will not sure about your model but it's worth a shot.Sometimes you need to install battery then plug in power cord.Good Luck
 
"Nvidia test failed, but unit does not qualify for QP

Today when I was using my MacBook Pro (Purchased Dec 2007) I noticed that the Internet was running painfully slow. I decided to restart the computer, and when I did, the computer would boot, but all I got was a black screen. I tried several different troubleshooting options, but ultimately took it to the Apple Store. On the Genius Bar Work Authorization Ticket, it reads, "Unit boots to black screen. Unable to run MRI. Nvidia test failed, but unit does not qualify for QP." In the Proposed Resolution section, it reads, "Drs for flat rate Main Logic Board replacement."

As I've read through some of the posts on here concerning similar issues, it seems that I should not be charged for the repair; however, I am being charged the flat rate of 310. Can someone help me out on this? Should I complain about being charged? If so, whom should I call?

Thanks,
Scott
 
Today when I was using my MacBook Pro (Purchased Dec 2007) I noticed that the Internet was running painfully slow. I decided to restart the computer, and when I did, the computer would boot, but all I got was a black screen. I tried several different troubleshooting options, but ultimately took it to the Apple Store. On the Genius Bar Work Authorization Ticket, it reads, "Unit boots to black screen. Unable to run MRI. Nvidia test failed, but unit does not qualify for QP." In the Proposed Resolution section, it reads, "Drs for flat rate Main Logic Board replacement."

As I've read through some of the posts on here concerning similar issues, it seems that I should not be charged for the repair; however, I am being charged the flat rate of 310. Can someone help me out on this? Should I complain about being charged? If so, whom should I call?

Thanks,
Scott

Hi Scott. This is thread about fixing backlight issues on unibody Macbooks (Late 2008 and newer). The issue you are dealing with is the famous Nvidia 8600m failures on the 2007 and early 2008 Macbook pro's which is unrelated to this thread. I personally don't know how Apple decides on the applicability of the 8600m issues but you might want to try searching for this topic in other threads or start a thread and ask the question. Good luck. Hope it works out for you.
 
Thank you. I am brand new to this forum so I was just looking for a thread that I thought sounded similar to my issue. Thanks again.
 
Where to buy the backlight fuse?

Hello Everybody!!

First of all I just want to thanks Dadioh for opening this thread and sharing his knowledge with us! I really appreciate your dedication!

Ok, I have at least 3 Mac boards with a blown backlight fuses. My question is where can I buy this fuses?? Mouser.com?? if so whats the specs I need to look for??
They're super small but I've been practicing removing stuff from dead boards and I think I'm ready now!!

Any help would be appreciated. Have a nice guys! :cool:
 
Good job. Unfortunately I don't have a schematic for the pre-unibody MacBooks and I am unable to determine if there is a similar circuit for the backlight. Maybe someone else with experience with these MacBooks can chime in.

There are two ICs in the center of the board that control the backlight. Then, there is an amplifier circuit on the I/O board. The A1226/A1260 machines have two different I/O boards. I am only intimately familiar with one of them, the 820-2273. If you can provide pictures of the board and the bottom of your I/O board, I can point out the components you may have to replace.
 
Liquid damaged Macbook White 2010

Hello Dadioh,
My macbook works good exсept backlight. Reading this thread I can find a backlight fuse (it's dead) and leddriver (looks like working - only 6 pins beeps to ground) but my LCD connector is badly looking (see pics). What could cause this damage? Does anybody seen this before? And if I replace LCD cable and fuse will it work? Sorry for my bad language, I'm from Russia)))
 

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