Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
As you can see the last two Pins look like crap.according to the schematics posted here those are the pins for the backlight(correct me if i am wrong).

My question is.
What do you suggest me to do?
Try disassembling the lcd and locate any fried component?
Try replacing the lvds cable hoping nothing else has gone wrong?
Or buy a new display assembly and get it over with?

Thanks again for all your help!

Ps:Hope the Apple Technician Guide i posted here helps some poor soul like it did for me.
;)

In all likelihood it is just the LVDS cable that is bad. The good news is those cables are fairly cheap now on eBay. The bad news is you have the glossy display then getting the glass off the front is a bit of an art form. Reeeeally easy to break the glass if you are not super careful. I would say, read a few guides, get yourself the tools (heat gun, suction cups, iPhone spudger tool) and have a go. Worst case, you break the glass and you are no further ahead.
 
In all likelihood it is just the LVDS cable that is bad. The good news is those cables are fairly cheap now on eBay. The bad news is you have the glossy display then getting the glass off the front is a bit of an art form. Reeeeally easy to break the glass if you are not super careful. I would say, read a few guides, get yourself the tools (heat gun, suction cups, iPhone spudger tool) and have a go. Worst case, you break the glass and you are no further ahead.

Thank you.
I actually have the hires antiglare display so i think it's a little bit easier.
Think i'll give it a try,maybe tomorrow.
Thank you for your opinion.
 
Here's a better trick: Instead of removing the old one, just stack the new one on top of the old and solder the two ends. since the old fuse is "open" it should cause no problem.

Then the solder pads that were engineered for the weight of one fuse will now bear the weight of two fuses. Further compounding this situation is that there are now two connections per side that can fail instead of one. Do not do this. You have a $2000 laptop, that is worth fixing properly!

You can get the old fuse off with a regular single soldering iron if you are careful. I do not recommend doing it this way, but it works without better tools. It is safe to say I wasn't using a Hakko FR-801 when I first started, while it is a great tool it did cost more than 1 month of my apartment rent. I put a bunch of new solder with no clean flux(i am assuming novices do not have separate flux) on each pad so the old solder wouldn't be as sticky. Blob it on as fast as you can to make sure you get a lot of flux there without it burning away. Then I heat the fuse itself with my iron at over 400c. both pads eventually heat up to the necessary temperature to get it off the board. This obviously does not work if you plan to reuse the component, but it is a blown fuse, so I don't care. Any remnants left behind are cleaned away with several q-tips and isopropyl alcohol.

The proper way to do it is with a surface mount rework station, or iron-tweezers. Dadioh's idea is also excellent, a ghetto version of those iron tweezers Hakko sells which are nothing more than tweezers that get hot enough to melt solder. However, Dadioh's method requires steady hands. I know my limitations, my hands jitter as bad as it gets before having parkinson's, so I personally wouldn't try it, but it probably works for Dadioh because he has good control of his hands.
 
Update!

Ok
So i went on with the operation!
I opened the display and removed the lvds cble.
The other end of the cable(the side connected to the display) looks like new and shows no sign of wear or any thing.the connections on the display also look perfectly normal.
Do you think it was just a matter of those two "bastard" pins i showed earlier?
Or maybe there's something else wrong inside the display?
Please share your opinions.
Thank you
 
a1297 schematic

Hello everybody!!

Any chance someone can forward a schematic for the Mac Pro a1297 Unibody
2009 board number 820-2610A

Any help would be greatly appreciated, thank you guys :)
 
Biiiiiig Thank You!

I just wanted to let you know i just installed a new LVDS cable and the screen is back to life...now i just gotta wrap everything up!

I want to thank you all for the help!
Sincerely

THANKS!!!
 
MacBook Air LED Backlight

I have just finished replacing a broken LCD on A1370 11" MacBook Air. It is doable but with a few caveat. Louis Rossmann correctly suggested that using appropriate heat gun to loosen the double sided adhesive is highly recommended. The bezel is metal and that is held by a clear and thin double sided tape to the top frame and LCD. The LCD itself is frameless (glass only and not a single metal frame surrounding it. It is glued to the top cover by a black and thin double sided tape. There are also 5 Philips head screws on the bottom that secures a thin metal strip (also glued to the LCD and needs to be reused for the new LCD). Removing the LCD requires the heat gun again, however the glued edge is less than 1/4" so heating it without a narrow nozzle heat gun will be a problem as directly under the LCD are several layers of thin sheets that polarize the 14-15 backlight LEDs. These sheets may warp/deform if too much heat get to the sheets.
Once the LCD is freed from the top cover, you have to remove 2 screws that holds a thin strip of circuit board with two connectors on it. This circuit board is permanently attached to the LCD via two flex cables on the left and right side. The board itself has a connector for the LVDS (with a bail for the securing it) and a much smaller ZIF connector that provides power via a flex cable to the background LEDs. The way this cable is mounted and the shortness of it makes it very difficult to orient it correctly on the ZIF. I ended up causing a PARTIAL TEAR on the flex cable, and now only half of my LEDs light up. Fortunately the polarizer did a good job of spreading the light and the side of the screen without LEDs has sufficient light to make it visible. So if you are working on replacing yours, pay attention how this flex cable is attached and folded to mate with the ZIF connector properly before you disconnect it. Oh, before putting in the new LCD (Rossmann sells this for about $100+), order a 2 mm double sided tape. Remove the old tape and clean up the area before applying the new one.

NOW my question: I have not been able to find anyone that sells this flex cable for the LED power. Anybody know where to get it? Perhaps that cable is also "permanently attached to the LED strip itself, but I have already glued the LCD, so I am not inclined to take that apart again if I am not sure I can get a reasonably priced replacement backlight/flex cable. The chinese sellers (Alibaba) sell complete top half assemblies, but that is several hundred dollars.
 
Macbook pro 13" 1278 2010

Dadioh,

Does the fuse with a letter P on it is needed to replace? I measured it and it has 0 ohm. I will take picture tomorrow.

Do you have schematic for MBP 13" 2011 A1278? Pls email me at seahawkgo@gmail.com. Thanks

Ben
 
Last edited:
part number

@dadioh

I bought the schematic for the early a1297 and found the mosfet I need to replace one problem thoug, the model number is SSM6N15FEAPE on a SOT563 package, any ideas where to get the equivalent??? Its for the wlan generation

Thanks!
 
@dadioh

I bought the schematic for the early a1297 and found the mosfet I need to replace one problem thoug, the model number is SSM6N15FEAPE on a SOT563 package, any ideas where to get the equivalent??? Its for the wlan generation

Thanks!

http://www.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&keywords=SSM6N15FE&x=18&y=14&cur=USD
 
0 ohms means the fuse is good so that is not the problem.

Dadioh, here is the picture

IMG_3122a.jpg

IMG_3121b.jpg


I am so worry that the LED driver or WLED chip is dead.

I purchased the schematic. I will email you the schematic when the seller email me the download link.

Thanks
 
Dadioh, here is the picture

I am so worry that the LED driver or WLED chip is dead.

Thanks

It looks pretty messy around the WLED driver. I assume this was a liquid spill? I would take a new toothbrush and some 99% pure isopropyl alcohol and give that area a good scrubbing to remove residue (with power removed and battery disconnected). It is possible that there could be some leakage through the residue causing an issue. Worth a shot anyway and you really should remove residue anyway to avoid future corrosion.
 
It looks pretty messy around the WLED driver. I assume this was a liquid spill? I would take a new toothbrush and some 99% pure isopropyl alcohol and give that area a good scrubbing to remove residue (with power removed and battery disconnected). It is possible that there could be some leakage through the residue causing an issue. Worth a shot anyway and you really should remove residue anyway to avoid future corrosion.

I used super alcohol to clean it twice before taking this picture. I also used head gun to dry it as 120 celcius degree. It worked for two hours then back light problem occurred. The P fuse is still good. Do you think the wled chip dead?

Have you check the schematic yet? In page 77 of schematic, does the P fuse of the board is F9700?

Do you know where is R0910 0 ohm resistor on page 8?
 
Last edited:
I used super alcohol to clean it twice before taking this picture. I also used head gun to dry it as 120 celcius degree. It worked for two hours then back light problem occurred. The P fuse is still good. Do you think the wled chip dead?

Have you check the schematic yet? In page 77 of schematic, does the P fuse of the board is F9700?

Do you know where is R0910 0 ohm resistor on page 8?

Wow those dark spots on the board looked like dried up coffee or cola and isopropyl alcohol will not remove them easily. If I were you, I'd disconnect everything on the board that can be unplugged/taken out, stick it in the dishwashing machine and do a short cycle. Let it dry and then some more air dry ( a couple days). the board should be as clean as the rest of the area unaffected. (I've done this with a Macbook a1181 LB in the past to clean it). Note that these LBs are wave soldered during manufacturing and go through a flux cleaning solution bath, so doing what I suggested is not far-fetched.
 
Wow those dark spots on the board looked like dried up coffee or cola and isopropyl alcohol will not remove them easily. If I were you, I'd disconnect everything on the board that can be unplugged/taken out, stick it in the dishwashing machine and do a short cycle. Let it dry and then some more air dry ( a couple days). the board should be as clean as the rest of the area unaffected. (I've done this with a Macbook a1181 LB in the past to clean it). Note that these LBs are wave soldered during manufacturing and go through a flux cleaning solution bath, so doing what I suggested is not far-fetched.

There are some deposits for which isopropyl alcohol is not a good solvent. In those cases water may dissolve them. Dishwasher could work but it depends on the hardness of your water. You don't want minerals left behind on the board when it dries. An alternative would be to get some distilled water and scrub the area in question to see if water is a better solvent for this particular spill residue. Then dry with your heat gun before powering up.
 
The problem with liquid & QFN packages is that all too often, alcohol and a toothbrush don't do anything good. All the connections are under the chip, an area your toothbrush doesn't get to. This is where ultrasonic cleaners come in. Heat the right liquid(a combination of bran-sonic EC & distilled water at 60c always does it for me), put the board in the bath, run the ultrasonic and little bubbles will get under the chip and rip all the crap off.

If you have good soldering skills, remove the WLED driver and look at it. It could have some ugly contacts. Remnants from liquid spills often move around over time which causes the problems.

My procedure on a liquid spill is to put the board in the ultrasonic bath with bransonic EC & distilled water at 60c for a few minutes. I turn it on and off while rotating the board.

Then I sit the board in a tray, which is a bath of isopropyl alcohol. Alcohol displaces water so this gets rid of all the distilled water. Then I use an alcohol bottle with a squirt-nozzle top to squirt the board while holding it, and squeeze to increase pressure to get underneath the chips. I'll point at the QFN & BGA packages and squirt into each side.

After this, it's off to the air compressor. The compressor is at 100 psi to 45 psi depending on what area of the board I am on so as to not cause damage, and this compressor did have a filter installed to ensure no dust/dirt/liquid comes out at the nozzle. The board is dried to the point of there being no trace of the alcohol on it, or under any chip.

At this point, there is no chance of further corrosion, and any minerals that may have been left behind breaking connections or creating new connections are gone. It's off to replacing components that have failed, and usually you have a good board.

Try to mimic this procedure in your own setup. I see boards where people have taken alcohol and a toothbrush to them everyday, but a lot of people don't do this effectively, which causes the laptop to still not turn on and function because the board is not yet clean. Beg, borrow, or steal a jewelry cleaner if you have to! See what you can do. If your backlight works for a few hours at a time, you are ahead of the people who have rotting LVDS connectors & blown fuses. All you need is a push in the right direction to have a working machine.
 
Anyone else with the non-Pro 13" unibody find a place to pick up a spare WLED? TIA

I ordered three of them (APP_1A) in China and I got five, so if still needed I can sell you one. (I live in the Netherlands.)

Unfortunately replacing the APP_1A did not work for me.
I have 12 V on pin 3 (power?), 3.9V on pin 5 (enable) and the fuse is not broken.
I found that pin 1 is the gate driver for the mosfet on the other side of the board. This pin has NO signal (checked with an oscilloscope). Replacing the APP_1A for another one or for the old one does not make any difference. (I'm quite comfortable in soldering SMD-parts.)

Anyone (Dadioh) any suggestions???

Oh, and is there maybe someone who has a schematic of the A1278 unibody? (I found one of the PRO-version, but not the unibody...)
 
Last edited:
The problem with liquid & QFN packages is that all too often, alcohol and a toothbrush don't do anything good. All the connections are under the chip, an area your toothbrush doesn't get to. This is where ultrasonic cleaners come in. Heat the right liquid(a combination of bran-sonic EC & distilled water at 60c always does it for me), put the board in the bath, run the ultrasonic and little bubbles will get under the chip and rip all the crap off.

... snipped.

Hemh, an opportunity for Louis to offer a service to us, for a fee? Most of anyone here probably could not afford to get all those equipment to fix our own system (I certainly couldn't, and the number of Mac's I played with cannot justify getting the equipment mentioned, plus my wife probably would not allow me to get more "stuff" in the house.
 
Hemh, an opportunity for Louis to offer a service to us, for a fee? Most of anyone here probably could not afford to get all those equipment to fix our own system (I certainly couldn't, and the number of Mac's I played with cannot justify getting the equipment mentioned, plus my wife probably would not allow me to get more "stuff" in the house.

Quite the contrary. I didn't pop out of my mother with a Hakko FR-801 and a Crest CP500HT. I made due with what I could get my hands on, and I am suggesting people here do the same. I became friends with someone at a local jewelry pawn shop, and begged them to use their ultrasonic cleaner in exchange for whatever I had at the time. A few bucks, beers. Just the gesture of offering something is more than enough if you are on good terms with someone.

Look at the WLED driver - on 13.3" Unibodies, it is at the top of the board. They say the board should be fully immersed to avoid damage, but the reality is you can get away with it being partially soaked and it will do just fine. While jewelry cleaners are not as sophisticated or purpose built for the task as a CP500HT, I will tell you they get under QFN better than a toothbrush, and if you know someone with one who will let you use it for free, you saved yourself the cost of buying a toothbrush!

If you REALLY want something done and do not have the MEANS to do it, you have to get CREATIVE! I want to encourage creative thinking. Yeah, more business would be lovely - but there are enough laptops flowing in everyday to beg for work on a public forum. The money made from doing actual work would make hundreds of dollars, vs. the 1-2 hours I spend giving free diagnosis & advice here making $0. It isn't about the money. This is more about giving back, to me, than anything else - and inspiring creative thinking in people who are where I was five years ago. I wish more people had done for me when I was a beginner, because the most expensive way to learn is to learn by yourself. I'm telling you what the problem often is, why it occurs, and how some people fix it. Run with that and figure out how to get it down your own way.

If you don't have the money or the ability to justify a new tool, you just have to get creative. I recall a string of bad business in December 09, back long before I had any sort of established reputation outside a little word of mouth. I received a call from a customer about a liquid damaged laptop. I'm down to my last $6 or so, and anxious to get something to help me not starve through the holiday season. I jump a turnstyle on the MTA subway to travel to them to collect the laptop, and jump a turnstyle on the MTA train back. I get back home, and notice a screw is obviously ruined and rusted. It won't come out. How do I remove the board to put it in the ultrasonic(that I had spent my "life savings" on at the time), and so I can replace components on the underside that are going to be rusted to hell? It's Christmas Eve at this point, hell if any hardware stores are open. I called over 48 of them. I finally find a place carrying Xcelite 175M, a beautiful tool for those who cannot afford a dremel because it is PERFECT at getting under rust ridden screws and removing them, even if they are very tiny. It gets the screw out. Alas, at this point, I am so low on cash I cannot even afford the distilled water to fill the cleaner, or the bus ride to the store to get some. I walk 4 miles to Duane Reade picking up dimes, nickels, pennies, and quarters on the sidewalk so I can pay the $1.99 tax for a gallon of distilled water at the pharmacy in the lovely NYC winter cold. I finally get there, buy the water, walk four miles back, and get home to my ******** apartment at the time, that doubled as a workshop. The rust is removed, and to my luck, only one stupid MOSFET on the back is actually rusted enough that it doesn't work. I swap it with a beautiful one off a board with a dead CPU, GPU, and RAMSLOT that had perfect power circuitry, using a Hakko 851 that I got off eBay as part of a business closeout sale for $35, and I run the board back. I collect my measly earnings and don't wind up losing 16 lbs over the Christmas holiday. December 25th-27th is a slow if not dead season for the independent technician. This is how I ate on Christmas of 2009!

A toothbrush cannot get under a QFN package. On newer boards, the LED driver is a BGA package, even more difficult to properly clean with a toothbrush. If you know the principle behind what you need to do, it makes it that much easier to macguyver your own solution, which is what I am trying to inspire here.

Rant over. Hopefully this inspires someone to revive their dead macbook without buying an ultrasonic cleaner!

----------

Oh, and is there maybe someone who has a schematic of the A1278 unibody? (I found one of the PRO-version, but not the unibody...)

PM me your email address.

----------

plus my wife probably would not allow me to get more "stuff" in the house.

Quite the contrary, owning a device that has the ability to service jewelry will make you the most popular member of a female-run run household. :D :) :)
 
Last edited:
I ordered three of them (APP_1A) in China and I got five, so if still needed I can sell you one. (I live in the Netherlands.)

Unfortunately replacing the APP_1A did not work for me.
I have 12 V on pin 3 (power?), 3.9V on pin 5 (enable) and the fuse is not broken.
I found that pin 1 is the gate driver for the mosfet on the other side of the board. This pin has NO signal (checked with an oscilloscope). Replacing the APP_1A for another one or for the old one does not make any difference. (I'm quite comfortable in soldering SMD-parts.)

Anyone (Dadioh) any suggestions???

Oh, and is there maybe someone who has a schematic of the A1278 unibody? (I found one of the PRO-version, but not the unibody...)

I had one of these that had an issue with the current sensing resistors being open circuit. The 2008 unibody has a pair of 1ohm resistors in parallel. The 2009 pro WLED driver doesn't use these resistors. You might check those resistors.
 
A1278 Early 2011 Backlight Problem

I need information regarding the backlight problem for Macbook Pro A1278 Early 2011. While trying to replace a broken hinge , I disconnected the LCD cable without noticing that the battery was still connected. After I could not see the backlight but the image is still there if I use a flashlight. Does anyone have component information,schematics, or check points? Thanks
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.