MacBook Pro Unibody - No Backlight - Logic Board Question

[blackburn]

You can find the DC-in board on eBay. I just ordered a few for $9. Make sure you get part number 820-2565-A. The magsafe from the 2008 Mabook aluminum is close but the screw holes don't line up.

I have repaired a few that were encrusted with liquid damage residue and corrosion by cleaning them and then using my hot air tool to reflow the solder. Need to be careful not to melt the wires. But for $9 for a new one I don't usually bother anymore.

Thanks! I re soldered all the connections and sometimes the mbp charges (I don't want to risk damaging the logic board), I will take a look on ebay and things like that to see if I can get the dc-in board + the top part since mine is dented on both sides and the glass is broken (the previous owner dropped it).

 

[bgt50]

Can you please check if the pins 1. 5 and 6 are connected to big black coil L9400 next to pin 6. Measure the continuity with the meter. pIN1 is marked with V. If they are connected, then pins 1'2'5'6 are connected tgether.Just bridge 1and2RegardsSent from my DROID RAZR

Thanx, yes they are connected.

 

[bgt50]

Can you please check if the pins 1. 5 and 6 are connected to big black coil L9400 next to pin 6. Measure the continuity with the meter. pIN1 is marked with V. If they are connected, then pins 1'2'5'6 are connected tgether.Just bridge 1and2RegardsSent from my DROID RAZR

Replaced the mosfet and had a picture for 2 minutes after switch on and then it went white again. Another place to look?

 

[zixu]

You should check first foe any shorts around and inside of screen connector.

Some bent pins inside. How your lvds connector cable looks like. Any damages?

To go bad it should got short from somewhere. If you saw the picture this means that screen should be Ok. Do you have spare lvds cable? Try it.

Motherboard repair is like surgery, you need to look carefully everywhere.

What was the issue with this mbp on first place? Liquid? Check for more oxidation.
Check for shorts to GND on all of the mosfet pins. Pin 1 on lvds connector is GND, Pin 2 is output voltage from the mosfet.

 

[perkalator]

Can anyone tell me is this is the fuse I am looking for? it is a 2009 A1342 2.4ghz. the MLB No is c0203020592dd161k. Thanks

 

[enxm2004]

Backlight problem on Macbook air, 11 inches model A1370, 2011.

Hi everybody
I am just new to this forum, i followed a little bit for the backlight problem and WLED and fuse problems.

I just replaced the lcd of my macbook air 11" and now the backlight does not work. when I turn on the laptop, the lcd works but the backlight does not turn on. I tested with a couple of screens but no success.

Do you think i have the same problem with WLED or fuse?

Is it possible to find WLED and the fuse easily on the net?

Thanks
Navid

 

[Musicsoul78]

MBP 2007 15" non unibody

No display what so ever no back light no image
Lvds is good
Screen is good
Just no display
Any ideas where to look for the wled driver or fuse on this board
Thanks guys

 

[perkalator]

Can anyone tell me is this is the fuse I am looking for? it is a 2009 A1342 2.4ghz. the MLB No is c0203020592dd161k. Thanks

Image

If anyone is looking back at this for an answer, I have confirmed that this is the fuse on this model

 

[dreds25]

Macbook pro A1278 unibody L8545SQ

hello all , back again , thankyou for all the help before , ive read through this whole topic again to try and get a better understanding of it all .
right so i have a macbook pro A1278 early 2011 ( i think ) maybe ate 2010 .So here is my problem ,
I have no image on the screen but i can get an image through an external monitor (no faint image with torch either )
i have tested the boost diode (black 74 or 7a next to the WLED driver this gives me a reading of 11.5 v
The 2a tiny fuse beeps when both ends of my multimeter touch either side of the fuse which means it has continuity which is good( well the fuse is good i think)
i have also tested all pins on the WLED driver and here are my results

pin1-000.6
pin2-6.88m
pin3-16.15k
pin4-99.2k
pin5-90.7k
pin6-24.8k
pin7-0
pin8-6.2k
pin9-000.7
pin10-7.21k
pin11-7.22k
pin12-19.5m
pin13-19.5m
pin14-0
pin15-0.6
pin16-0
pin17-0
pin18-0
pin19-9.82k
pin20-10.00k
pin21-0.468m
pin22-17.4k
pin23-17.33k
pin24-350k and up (kept rising and my arm stared hurting lol )

i thought that my WLED driver had gone and im just posting these reults so that someone could confirm this ,
I have referenced these with Dadiohs findings on the first page and i know that there is a big difference which leads me to believe that the WLED is at fault
Could someone confirm or deny this ., Thankyou for any help ,
as you can see im new to this and just doing this as a hobby in my spare time as i find this very interesting
I have a L8545SQ chip coming and a going to try and replace this myself if it is the fault , not a master solderer but im ok and am willing to try this
I am also attaching a photo of the chip in question just to make sure i have read the pins correctly , pin 1 and 2 are marked to make sure i was going in the right direction lol
thanks alot and any help will be hugely appreciated
thanks
dreds ( noob trying to learn )

 

[l.a.rossmann]

desoldering the blown mosfet got me a nasty pcb burnspot with 1 connection missing. Do you know where the legs of the chip are connected to?
Image

If you tell me the 820 number of your board I'll check on one of mine. I don't have a schematic for pre-unibody stuff.

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Can anyone tell me is this is the fuse I am looking for? it is a 2009 A1342 2.4ghz. the MLB No is c0203020592dd161k. Thanks

Image

That is it!

 

[gb123]

Do you have the install DVD for apps that came with the MacBook? That has Apple Hardware Test on it. With DVD in drive hold down the D key while booting and it should start AHT. Run that and see what fails. Might give a better idea.

So, after much research, I was finally able to get the AHT to run (not easy since I had done several clean installs and have no install DVD, or DVD drive for that matter). Here is the only error code I got: 4SNS/1/40000000: ThOH-92.125

After a bit of Googling it seems that this is an issue with the heat pipe temperature sensor, which doesn't seem particularly relevant (though by the time the extended test finished the whole computer was terrifyingly hot so maybe it caused its own issue ).

A couple points: after more usage, it seems that the backlight will actually turn on after leaving the machine on for some time (a few minutes to a few hours), and once this happens it will actually be good for a few days (turning off and on, putting to sleep and waking, etc. are all fine). Then the issue will start again, and no trick reliably gets it working again other than leaving it on and waiting. Moreover, though I got the AHT running during one of the "dark periods", the light turned on just as I started running it, so I don't know if it would have caught the issue

Thoughts?

 

[elitetek]

820-2936-a lp8550tle pin1

HELP!

While replacing the WLED driver from a 820-2936-A logic board I noticed that there is no PIN 1 marked on the logic board. It is a high-efficiency 25-pin BGA LP8550TLE. If the the LVDS connection is located at the top right corner how where is PIN1 or how which way is the package supposed to be reflowed.

-Thanks

 

[mousepad]

HELP!

While replacing the WLED driver from a 820-2936-A logic board I noticed that there is no PIN 1 marked on the logic board. It is a high-efficiency 25-pin BGA LP8550TLE. If the the LVDS connection is located at the top right corner how where is PIN1 or how which way is the package supposed to be reflowed.

-Thanks

Then Pin 1 is down on the left!

 

[Tjw1978]

2009 a1297 820-2390 a liquid damage question

Wow..so much information and help in this forum. I read this entire thread and with so many models and configurations I'm now a bit confused. I have the above Mbp. Ordered it as a parts/non working unit. No power nothing. With the help of this forum I took out the logic board, cleaned 3 times in an ultrasonic cleaner, rinsed 3 times in ultrasonic cleaner, scrubbed with tooth brush and cleaner, rinsed again in ultrasonic, dried in a 160 degree convection oven for 4 hours. Reinstalled the board and attached MagSafe and get the following...
Bright green on MagSafe. Press power button and fans kick on, turn off then back on. No display. Connectors on LCD cable pin 1-3 are shot. Have another cable coming. No beeps no dings on power up. Multimeter is at home so I will get that. Do not hear the cd drive spin, do not hear the hard drive...but wouldn't as its a ssd..lol. MagSafe does not turn orange. So... Where should I start? I'm thinking because of the fans spinning its a good sign? I also reset the smd and tried the pram but because of no dings on start up not sure what next step is...

Board is very clean no signs of corrosion or burnt connections anywhere. Cleaner I used is formula d from the restaurant store. Amazing cleaner and does not damage board. Cleans sticky residue, grease, as well as corrosion and black carbon deposits. Rinses completely with distiller water..NO residue at all. It's a food safe cleaner and what I had on hand so I tried it and it worked great. Got my board to at least turn the fans on...

 

[elitetek]

Thank you for your help mousepad! I got the machines working. I actaully just received a liquid spilled macbook air A1369 logic board # 820-3023-A. I checked the backlight fuse marked "P" and it is open. It also has damaged the LVDS connection, and cable, which i will replace. However does anyone know were is the WLED located on this logic board?

 

[elitetek]

The keyboard controller is just north of the keyboard connector. Check that it's solder connections are all good.

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There are many many things that are beyond just the ability to charge the battery. Charging battery does rule out common issues with magsafe and g3Hot but there could be SMC issues, power rail issues (5V, 3.3V, 1.0V, etc...). First thing to try is an SMC bypass. I have another thread with that info in it.

I know this is off topic about the backlight but I would like to take this opportunity to thank everyone for the help and this thread is quite amazing so much experience.
Well as the title says I have a Macbook Pro 15" A1286 will not turn on. This happened after the battery died. The strange thing is that the battery charges fine and the magsafe opreates perfect however the it will not turn on? I have done a SMC reset and PRAM reset. Does anyone know if the SMC QFN chip have failed or where I might start looking? The logic board looks clean.

-thanks

I did a smc bypass and it worked a few days until I left it overnight. doesn't want to boot up. The logic board is 820-2330-a, if anyone can help on measuring the power rails or were should I start I would apperciate it.

-Thanks

 

[macattack600]

a1278 2011 I7 2.7 13"---Need help identifying Component

Needing some help identifying this component left of the wled driver it's in bad shape. The P fuse here was previously worked on with jumper wire. I've taken the wire off and I get continuity from ground --from one side and not the other I suppose I need to work off that not just expecting to replace only the fuse is there a good way to go about testing the wled it's different from the other a1278 any tips?

 

[elitetek]

Macbook air A1369 820-3023-A WLED driver

So I discovered that the wled driver is located on the back of the logic board, however can anyone confirm that the wled driver used is LP8550TL/NOPB?

 

[FuLL]

Hi folks..

I have a problem with MBP early 2011. i have two of them and the other got liquid damage. Backlight flickering once in a while..

i tryed to measure voltages while computer on but somehow i managed to kill something and now screen shows stripes on it..:/

tryed screen with working logic board and got backligt with stripes :/

so i killed the t-con board of the screen and have wled faulty logic board

I ordered some wled samples and i'm going to buy a new screen from ebay... let's see after that.

Cheers.. very useful info here.

 

[l.a.rossmann]

I have seen those videos before and they do have some really nice tips. But be aware, he is showing soldering on what looks like a 2 layer circuit board with sparse component population. In real life, on a Macbook, you are looking at 12 to 16 layer circuit boards (which wick away heat very fast) with very dense layout and a lot of 0402 size parts. So it takes a LOT more heat and patience to achieve results.

Just to let you know before you are greatly disappointed in how easy he makes it look and trying to figure out why it isn't working so easily for you

I finally put my money where my mouth is and made a more descriptive video. It only took six months.

Here is a semi instructional video, to help familiarize people who are diving into QFN soldering to get their macbook working. Fast forward to 4:15 and there is a camera pointed straight at the board so you can watch the entire process. May all of you do better than me.

I forgot to mention in the video, the iron is a Hakko 936, and the rework station a Hakko FR-801. You can save a lot if you buy some Aoyue stuff, they have caught up big time.

 

[FuLL]

MBP 2007 15" non unibody

No display what so ever no back light no image
Lvds is good
Screen is good
Just no display
Any ideas where to look for the wled driver or fuse on this board
Thanks guys

this usually means that nvidia gpu has separated from the logic board.
like this.. http://www.caltexsci.com/TL_BGA/BGA pictures/BGA crack1.jpg

it's not easy to repair and usually the only permanent solution it to reball gpu.. you can reflow it aswell but it's not that good.

 

[SirgMFK]

Is anybody know where I can get this video chip (216-0810084) for MacBook Pro 15" A 1286?

Ati 216-0810084: (HD6770)MacBook Pro 15" A 1286 later 2011

 

[widerstand]

A1278 backlight

Hello!
I am trying to repair a spilled A1278, K24, 2.26 model.
SMC problems are bypassed with success, so starts up and charges.
Only problem is the backlight, cant get it back.
Maybe the LED driver is the problem.
On the diode next to the WLED i measure 0 volts - bad news.
I had to replace the big white capactor from an other board - how do i check it if it's ok?
The fuse was also removed. on the upper pad i can measure something around 12volts. Is it the PPBUS_S0_LCDBKLT signal? does it come from the smc, so it is an "enable" voltage?
What voltages should i measure on Q9806 FDC638 and on the Q9807 SSM6N15 pins?
FDC638 is on the wled side, not on the GPU side, right?

From measuring the backlight ic, i get a bit different values, some pins show open. Does it make sense to spend money on the wled ic? help would be much appreciated, if something else is toast, it will end up in a desktop mac...
Thanks in advance
ZSolt

 

[zixu]

this usually means that nvidia gpu has separated from the logic board.
like this.. http://www.caltexsci.com/TL_BGA/BGA pictures/BGA crack1.jpg

it's not easy to repair and usually the only permanent solution it to reball gpu.. you can reflow it aswell but it's not that good.

FuLL

Normally when gpu is separated, mbp shouldn't work on external screen also.

And there should be no reactions on keyboard lights when u press buttons and any chimes or screams.

 

[healeydave]

Ok, I had a Macbook Pro only 6 weeks old that had backlight issues (Ref: Post 1007).

Unfortunately, the backlight failure resulted in burn-out damage through to the LVDS connector (the worst case scenario).
Fortunately though, I managed to get the unit repaired under warranty, so the Logic board and the LCD have been replaced!

I had noticed a peculiarity prior to the unit going for repair which I have not seen mentioned anywhere before and its come back with the issue still.
The last LED of the battery checker is permanently illuminated (see Pic) even when the unit is powered down.

I did think this was probably an issue on the Logic board, but as this has now been changed, I guess it must be something else and obviously missed by the repair technician.

Anyone seen this before or know what could be causing it!?!?