MacBook Pro Unibody - No Backlight - Logic Board Question

[pedral]

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.

Thanks for the fast answer.
My knowlegde is poor in electronic,but i could use a multimeter if needed.
I've checked the lvds,and the last pin on the right is burned. Before i goany further, what needs to be done? Should i "clean" the pin and plug it back safely?

but solving this would just bring me back to my first problem: the backlight
The screen i bought said asnewisnt really, could it come from that? (the seller has very good rating though)

Thanks

 

[pedral]

By the way the backlight was working before i broke my ol screen

I tried to scrap the pin and plug it back, didnt work

 

[Dadioh]

Thanks for the fast answer.
My knowlegde is poor in electronic,but i could use a multimeter if needed.
I've checked the lvds,and the last pin on the right is burned. Before i goany further, what needs to be done? Should i "clean" the pin and plug it back safely?

but solving this would just bring me back to my first problem: the backlight
The screen i bought said asnewisnt really, could it come from that? (the seller has very good rating though)

Thanks

When you say "last pin on the right" do you mean the pin closest to the hinge or the pin closest to the battery?

Also, which Macbook are we talking about? The 13" or the 15"? Makes a difference which pin we are investigating.

 

[pedral]

When you say "last pin on the right" do you mean the pin closest to the hinge or the pin closest to the battery?

Also, which Macbook are we talking about? The 13" or the 15"? Makes a difference which pin we are investigating.

I've got the macbook pro 15 2.4ghz I5 Mid 2010. 15 inches macbook pro 2.4ghz I5 nvidia330m.
The pin is silver now


Do you think its the motherboard or the screen who have been damaged?

Thanks

 

[Dadioh]

I've got the macbook pro 15 2.4ghz I5 Mid 2010. 15 inches macbook pro 2.4ghz I5 nvidia330m.
The pin is silver now
View attachment 412471

Do you think its the motherboard or the screen who have been damaged?

Thanks

Hard to say if it is the screen or the logic board. Depends on what got stressed when the connector was wiggled. Could be the source (logic board) if the termination point got shorted. Or could be the termination (Screen) if voltage got applied where it should not.

Only way to tell will be to plug in a know good monitor and see. Once connected do not move the connector at all. It will either make contact or not.

 

[pedral]

Hard to say if it is the screen or the logic board. Depends on what got stressed when the connector was wiggled. Could be the source (logic board) if the termination point got shorted. Or could be the termination (Screen) if voltage got applied where it should not.

Only way to tell will be to plug in a know good monitor and see. Once connected do not move the connector at all. It will either make contact or not.

Ok, thanks very much for the help Dadioh, i think i will stop here, cause i dont see how i'm gonna find which is the little thing to fix. I'll use it as a desktop computer for the moment(even i really need portable and i've got all pieces new, aahh frustrating...), and i'll try maybe later with another screen, if the budget comes

 

[jrumball]

So.... this seems like the best place to post this

I have a Early 2009 MBP 15.4 2.8 C2D 8gig Ram 512mb Nvidia 9600m GT with shared 9400m 1680x1050 matte LED LCD 750gig Disk osx 10.8.3

I purchased a MBP on Ebay the only problem that was mentioned was a flashing question mark in a folder, and what looked like to be a flaky display cable the screen went on and off with the movement of the hinge and explicitly no liquid damage, I thought I had got lucky as i won it for £300 popped in a new disk and replaced the HD cable, replaced the display cable, it was a matte model so at the same time I upgraded the display to a 1680x1050 LCD and away I went. All has been good for the last 6 months.

In the last week I have been having major display issues with the internal LCD, I could resolve these by putting pressure on the left hand speaker grill above what I now know to be the WLED driver. Initially this seemed to coincide with the cooling of the machine ie after graphically intensive activity which is what lead me to reflow both GPUs as I have seen conflicting reports of whether some 9600m cards had similar problems to the 8600m

The machine works perfectly closed with an external display via Mini DP to VGA adapter, what I'm typing this on now ! Which makes me suspect somthing post GPU, to do with the LCD output stage.

Using gfx control to force both GPUs these problems still happen on both

Symptoms

Distortion on the internal LCD from boot, tearing the screen going black, the back light still functions %95 of the time.

The machine will occasionally hang just after login in OSX and hangs after the windows login screen too.

When it hangs in osx it reports back with an Nvidia Driver error on next login.

All of these happen in both osx and windows.

What I have tried in no particular order

-Reset pram and smc
- removed reseated and swapped RAM
- buzzed out replaced LVDS cable and swapped cable and original display
-selectively reflowed both GPU and GPU/northbridge with hot air
-baked whole Logic board in oven in an attempt to catch a dry joint I hadn't noticed
-replaced heat transfer compound
- carefully inspected logic board and LVDS connector no glaring problems
-checked back light fuse
-swapped mag safe adapters
-booted from usb installer disk

.....none of this has made it better or worse but the issue is still present....

Anyone have any ideas, I'm thinking bad GPU, or broken trace on Logic Board some where, or something to do with the WLED Controler but am open to try anything else to get it working...

Have tried a few more things but its late and can't remember......

Many Thanks for reading all of my waffle

Bump any ideas Please !

 

[glyx]

HELP same problem here!!!

Is it a BGA package? The previous models all used QFN packages for the WLED driver. The QFN's do have a thermal pad underneath them to conduct heat out of the part. That makes them a little more difficlt to remove but still you should be able to heat it enough to reflow the solder.

Holy cow! guess what, my macbook is back on duty

i ordered the samples from NS and it took only 2 days shipping from singapore to germany with UPS Worldwide express. Thanks National

only thing i experienced is: the new chip does not have dithering, so you see the dimming steps. but thats a flaw i can live with.

thanks Dadioh for your support. and if anyone ever needs a LP8550 do not hesitate to contact me. or otherwise just get some samples from NS

So please dear friend i have to ask for one piece of this LP8550 LED driver....
If you could please help me... Tell me how....
THANX
Glyx

 

[enxm2004]

So please dear friend i have to ask for one piece of this LP8550 LED driver....
If you could please help me... Tell me how....
THANX
Glyx

Hi
I also got this LP8550 from TI but since they are BGA, it is really hard to change them...

 

[glyx]

Ok with soldering


So only the first time is a real pain in the....
After that is not so hard to do it......
THANX

can i have the chip???? pls...

 

[Mori3000]

Hello every body

I have got a MacBook Pro 15" with part number 820-2915-A

I replaced the headphone jack and after the replacement i recieve the sound only from the right side speaker and the left one has stoped working.

what could the problem be?

Please help

 

[NeoGzz]

Macbook Pro Backlight fail

Hi, I´m new in this site, and I´m having the same problem, today my mac book pro A1229 fail the LCD back light, I search over the Internet, and find some things to do, like reseting the PRAM, taking the battery off and pressing the power button for several seconds, disabling some display and energy settings and after doing all this things I have no luck..

I connect an external monitor and there seems to be working everything else

So here i am asking help and directions on how to start diagnosing this laptop, and what should I do first.

On January opened this laptop to upgrade the HDD, so I don´t have a problem looking inside, I´m a newbie guy here, but willing to learn and fix this problem!!

I hope you guys can help me.

Thanks in advance!!

 

[ReD-BaRoN]

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?

Image

Elitetek, did you get this 820-3023-A board working? I need to replace LVDS connector on the logic board, and wondering which part is needed and how you did it.

 

[ReD-BaRoN]

That is what I expected. What I said in the earlier post was

If the pins are corroded off then you are really just left with replacing the connector. You "could" try bridging solder from the logic board to the stubs on the connector but being corroded the solder probably won't stick and you would likely melt the plastic of the connector.

Replacing the connector is really not that hard. I have done many of them.

The steps I take are:

1) Remove the old connector with a hot air tool. This destroys the connector but you are throwing it out anyway.
2) Clean the solder completely off the ground pad and off all 30 (or 40 for 15") pins. You want the new connector to sit absolutely flat on the pads without solder bumps holding it up off the board.
3) Apply liquid flux to the area including the ground pad and pins.
4) Place the new connector being careful to align all of the pins on their respective pads.
5) Using fine tipped soldering iron apply a small bit of solder to both ends of the connector shield to tack it in place so that it does not move. It takes a bit of time to heat the ground pad enough that the solder will stick to it. Patience is key.
6) Once the connector is tacked and securely held in place, then start at one end and solder each pin to its corresponding pad. Apply only enough heat to get the solder to flow onto the connector legs. Too much heat endangers the plastic of the connector.
7) Once all of the connector pins are soldered to the pads I move along all connections with a fine dental pick pressing very gently and observing under microscope for any movement. This ensures solid connections and detects incorrect solder connections.
8) Now run a bead of solder along the front edge of the ground strip of the connector. It takes a fair bit of heat to get the ground pad hot enough to wick to the solder so, again, patience.

Done! I think that the trick is that you have to use manual soldering iron technique. Hot air tools are usually too hot and will melt the connector plastic. Maybe it can be done with precise temperature control but the manual soldering iron works every time.

Good luck.

This what I need to do, any videos?

 

[vernski]

Hey all, i've blown up a inductor on my early 2011 MBP. And cant find a part number, or any information to find a suitable replacement.

I've linked a photo, its the inductor with markings 330 on its top.
any help would be great

Thanks

http://i1314.photobucket.com/albums/...ps0cd1f460.jpg

 

[vernski]

Hey all, i've blown up a inductor on my early 2011 MBP. And cant find a part number, or any information to find a suitable replacement.

I've linked a photo, its the inductor with markings 330 on its top.
any help would be great

Thanks

http://i1314.photobucket.com/albums/...ps0cd1f460.jpg

sorry that link didnt work, try this one:
http://i1314.photobucket.com/albums/t580/vernsk1/2011_G3Hot_zps0cd1f460.jpg

also i believe it is L6995 but cant find any other information.

 

[cetchmoh]

sorry that link didnt work, try this one:
http://i1314.photobucket.com/albums/t580/vernsk1/2011_G3Hot_zps0cd1f460.jpg

also i believe it is L6995 but cant find any other information.

Hi!

Usually those are from toko. The 330 indicates that it is a 33uH inductor, but you should definitely confirm this with the schematics.
I cannot really make out which package it is but to me it looks like a D53LC.
You can find it here:
http://uk.rs-online.com/web/p/wire-wound-surface-mount-inductors/7381198/

Cheers

 

[lagstarr]

Having Problems Identifying the Backlight Components

First Post And It Is A Doozie,

I have a A1278 2010 model and the board powers on fine you hear the system start up but do not have any display you see the screen darken when it is powered on, thought this might be a GPU problem so I reflowed the chip with no success still having the same issue, I need help identifying the backlight components of this board,

and following the photos and other posts i still cannot find the fuse and caps that were being talked about

 

[cetchmoh]

First Post And It Is A Doozie,

I have a A1278 2010 model and the board powers on fine you hear the system start up but do not have any display you see the screen darken when it is powered on, thought this might be a GPU problem so I reflowed the chip with no success still having the same issue, I need help identifying the backlight components of this board,

and following the photos and other posts i still cannot find the fuse and caps that were being talked about

Take a look at the lvds socket on your pics. The first square package to the right of it, that's your WED driver. Are you sure that this is a 2010 model? Did someone already rework this board? In the upper left corner from the WED driver I see 2 caps in a 0603 package. The left one looks reworked, and I would actually expect a fuse there.

 

[vernski]

Hi!

Usually those are from toko. The 330 indicates that it is a 33uH inductor, but you should definitely confirm this with the schematics.
I cannot really make out which package it is but to me it looks like a D53LC.
You can find it here:
http://uk.rs-online.com/web/p/wire-wound-surface-mount-inductors/7381198/

Cheers

you sir cetchmoh are a legend! thank you

 

[lagstarr]

@cetchmoh

could you mark the spots from the pic to where i should be looking exactly this was a liquid damage board and the only problem left is getting the backlight back,

also I am not sure if this was reworked in that area, it was dropped off @ my shop not even able to boot let alone power on after a intense 99% alcohol bath and a GPU BGA reflow the system booted

 

[yair27]

Hello i have macbook pro 15" 2011 boad 820-2915-b and i cant find the backlight fuse (f9800)..can some one show me at the picture where is it?

 

[agencik]

MBP 15 2009 backlight problem

Hi, I bought this MBP on ebay with no backlight and reading your posts I was able to sort this out but I'm getting one problem every 4th or 5th diode does not work
So to get in to this place where I'm now, I've replace already resistor 300k & 6 leg smd 638z next to the wled driver and I've replace also 40 pin lvds connector and now I end up on one row led not working
so if can ask for help I'll be grateful to anyone. Thx

PS what i did check is that that I'm getting 37v on 38,39,40 pin on lvds con and on 2, 3 2.5v, on the boost diode next to the wled D 33v
resistance on wled driver looks like is ok compare to the thread on the first page

http://i1201.photobucket.com/albums/bb347/agencik/IMG_0657_zpsfe63067c.jpg
http://i1201.photobucket.com/albums/bb347/agencik/IMG_0665_zps8d8aa183.jpg

 

[elitetek]

Macbook A1342 missing component

Purchased a Macbook A1342 logic board 820-2567-A. Found a missing component (cap) just below the LVDS connector. I thought this would be the best place and forum to see if anyone had schematics.

Thanks Again!

 

[CoolDaddy]

After finding this thread, I checked the fuse, which was blown, and had it replaced by someone who could solder something that small. It didn't fix the issue. The issue is that I can see an image on the screen with a flashlight, but no backlight. I think the issue may be with the LVDS cable and possibly even the LVDS connector on the board. Let me know what you think. Thanks!