MacBook Pro Unibody - No Backlight - Logic Board Question

[Sold]

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...

i change the fuse like in post 182 made by you
https://forums.macrumors.com/threads/972699/

initial i don-t have light...but on external working good...
i repair light change fuse...i put the original display light work and vertical stripes apear...

after that i try another display lg......and i put again original display...only light 27v at backlight voltage point at rezistor 125 but no light..

PLEASE indicate on display conector pins what to measure at all pins they indicate something...

THX

 

[aqibi2000]

Please help me somebody,

Quote:
Originally Posted by aqibi2000
Dadioh can you please please assist me post Number 606. Thank youuu
Hi. I don't have any experience with the A1342 so I hadn't responded. Also, that model uses a different backlight driver from the aluminum unibodies. But from what you describe that backlight driver is detecting a problem... probably over current, and shutting itself off. You will need to troubleshoot that circuit but I am not the right one to help. Sorry.

My Mac has lost its backlight, and i need to know how to test the WLED Driver circuitry. I have a Amprobe Digital multimeter and Jovy Systems Rework equipment, from which I repair GPU's on a daily basis but not circuitry.

I'm sure somebody out here can help with regards to my A1342 tripping out the backlight; as it down briefly try to power it but cuts out (0.000001 second upon power up). Apart from that works 100%

The fuse shows 12V, but I don't know how to test the other circuity..

This is the best forum I have ever visited. Everyone is so helpful keep it up guys.

Here is schematic : http://ifixit-documents.s3.amazonaws.com/OlSa6sc46JKxNuUO.pdf


Here I did a diode test on the Caps all others showed some form of reading even 0.00, but this one indicated never and showed (O L etc)



This image should help explain, can somebody assist me, or it it invalid conducting a diode test in any way shape or form on a capacitor anyways.

 

[floam]

So, my 15" mid-2009 Macbook Pro (2.8GHz CTO, A1286) suffered a spill...

And here's a photo the bottom of the logic board near the LVDS connector. The WLED driver (a L8543SQ) is the square chip below the screw hole, and I'm pretty sure the fuse is the little guy with a dot a bit over to the right. I checked the resistance on the fuse and got 0.3 Ohms, I think. Or my probes were touching, who knows. They're not nearly precise enough to be doing this. But I'm pretty certain the fuse is fine as I wouldn't get any backlight if that were blown. LVDS cable connector and the connector on the board looked perfect to me. Gave the whole WLED area another once over with alcohol and a brush now that I know where that is. I see some tests others have done but unfortunately this is all on the bottom of the board and not easy to get to when the system is running. Is there anything I can do to diagnose this further from the top, with the clunky probes that came standard with my Fluke 114?

Thanks!

 

[babyboo]

Thanks Dadioh for help, I just replace the 2A fuse with a dot. i use multimeter DCV 200 Not 200M. The fuse one side is 12.1V other side only 8.7V, and WLED Drive Pin 4 shows 00.1, When I change DCV 20 WLED pin4 show 0.06. do i need to change both. or just replace WLED drive.

 

[Astroboy907]

Gaaaaaaaaaahhhhh!!!!

The fuse sees 12V nominal so 32V is plenty. Get fast acting variety. It is a 2A fuse.

On the first post I was new to the whole thing and was wondering if the white device was a fuse. It turns out that it is NOT a fuse. It is a 200pF capacitor on the backlight output. Replacing it with a fuse would be a big mistake.

Ok, Daidoh, here goes.

Ordered a fuse on thursday- it is linked in above post. Fuse got here today (go mail!) andI set on to try to fix this problem. I measured the precious fuse as blown ( yay! ), and went ahead putting a new fuse in. At first, I just soldered the new fuse on top of the old one (I had a super hard time getting it off....). Powered on, did SMC and PRAM resets, nothing. Tried again and got much better results soldering wise (got the old one off), but I power on and it is still the same problem. No backlight, whatsoever. ****.

As of now, I have no idea what to try next. I suppose I could go and check the WLED, but I have no idea how to test it. As for voltages, I dont even know how to check, and my fuse is on the opposite side of the board. I really dont have any idea what to do next. Please help, I spent some $500 on this, and I really want to fix it. Please advise.

Edit: Also, something strange, when i plug in the magsafe after disassembly, it is dim. Took it off and plugged it back in and it was fine. Strange....
With super thanks, A907

 

[Macman756]

Ok, Daidoh, here goes.

Ordered a fuse on thursday- it is linked in above post. Fuse got here today (go mail!) andI set on to try to fix this problem. I measured the precious fuse as blown ( yay! ), and went ahead putting a new fuse in. At first, I just soldered the new fuse on top of the old one (I had a super hard time getting it off....). Powered on, did SMC and PRAM resets, nothing. Tried again and got much better results soldering wise (got the old one off), but I power on and it is still the same problem. No backlight, whatsoever. ****.

As of now, I have no idea what to try next. I suppose I could go and check the WLED, but I have no idea how to test it. As for voltages, I dont even know how to check, and my fuse is on the opposite side of the board. I really dont have any idea what to do next. Please help, I spent some $500 on this, and I really want to fix it. Please advise.

Edit: Also, something strange, when i plug in the magsafe after disassembly, it is dim. Took it off and plugged it back in and it was fine. Strange....
With super thanks, A907

You probably shorted that cap, or flux/solder shorted something surrounding it.

 

[Astroboy907]

You probably shorted that cap, or flux/solder shorted something surrounding it.

Yes, thanks again for this. Try going back a page and looking at my linked image. The part I replaced was a fuse, located directly underneath the bottom of the start if the arrow. I understand the pic is pointing to a cap, I justaren't reused the image. The part I took off had a dot on top. And if I am completely wring, and the part with a dot on top is a cap, would you be so kind as to tell me the values of it?????

 

[Macman756]

Yes, thanks again for this. Try going back a page and looking at my linked image. The part I replaced was a fuse, located directly underneath the bottom of the start if the arrow. I understand the pic is pointing to a cap, I justaren't reused the image. The part I took off had a dot on top. And if I am completely wring, and the part with a dot on top is a cap, would you be so kind as to tell me the values of it?????

That's wonderful, but it's an IC, just make sure no flux or solder got past and shorted other components, and make sure your botched fuse is connecting to the board on both ends, not just to the faulty fuse.

 

[Astroboy907]

That's wonderful, but it's an IC, just make sure no flux or solder got past and shorted other components, and make sure your botched fuse is connecting to the board on both ends, not just to the faulty fuse.

Eventually got the faulty one off, no problems there (now). Fuse is connecting to board and multimeter checks out fir both sides. I got a 1.2k resistance between the left side of fuse and the lower "ground plane" ( I am assuming it is that)

As for flux, used none, I was able to solder on to the pad verrrry carefully. Took me a while, but hey, it worked

Backlight still doesnt work, but I found a schematic and board file so I will be checking for proper resistance values and caps tomorrow.

 

[activa]

Do you trust ebay repair shops?

Hi, I have a 2010 17" MBP A1297. Water damage--all seems to work fine except backlight. I soldered a thin wire across the open fuse and now I get a brief flicker at startup sometimes when the machine has been cooled down for a while, but other than that nothing.

My question is whether anyone with this problem has tried any of the numerous ebay services that offer to fix such problems (prices usually range from $200 to $250).

Of course, if anyone recognizes the symptoms and can point me to the exact component AND self-repair is a possibility I'd be eternally grateful.

Or, if anybody here has the pro equipment and wants to make an offer for the repair I'm all ears.

 

[snowwiz]

ipex 30-pin connector source?

I'm looking for a replacement 30-pin connector for the LVDS cable on a mid-2010 13" macbook pro. I've read through this very interesting and helpful thread, but didn't recall seeing a mention of where to purchase this component or what exactly it is called. I've search for various combinations of "ipex, 30-pin, LVDS, connector" on google, ebay and sites like digikey and mouser, but am not coming up with anything. Can anybody tell me what this connector is called and where to buy it?

Thanks!

 

[Astroboy907]

I'm looking for a replacement 30-pin connector for the LVDS cable on a mid-2010 13" macbook pro. I've read through this very interesting and helpful thread, but didn't recall seeing a mention of where to purchase this component or what exactly it is called. I've search for various combinations of "ipex, 30-pin, LVDS, connector" on google, ebay and sites like digikey and mouser, but am not coming up with anything. Can anybody tell me what this connector is called and where to buy it?

Thanks!

iFixit.com has many of them, just search by your model. On ebay you can get them cheaper and search XXXXXX (yuor model #) and LDVS.

 

[Sold]

Please help...

please help

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...

i change the fuse like in post 182 made by you
https://forums.macrumors.com/threads/972699/

initial i don-t have light...but on external working good...
i repair light change fuse...i put the original display light work and vertical stripes apear...

after that i try another display lg......and i put again original display...only light 27v at backlight voltage point at rezistor 125 but no light..

PLEASE indicate on display conector pins what to measure at all pins they indicate something...

THX

 

[peislander]

Has anyone bought the cheaper aftermarket front glass for the 13 inch Macbook or Macbook pro?Just wondering if it fits good & looks original or should I look for original.Can anyone recommend an Ebay seller that sells them.Thanks

 

[2bit]

External Displayport question

I have a Macbook 2.26mhz A1342 logic board. The situation is I can see the fan spin and hear the superdrive spin as well as the hard drive, so the logic board is trying to come up. The problem is I can't see anything on the screen. The display, the display cable and logic board display circuitry are all unknowns. I was told that this logic board works, to me it's still an unknown until I can verify that. The display and cable have been through a liquid spill so they are definitely unknowns. My question is using a Mini Displayport cable can I bypass the internal display and have the video output go to external display? If so, are there any special keys or key sequence I need to press to engage the external display? The 30 pin I-PEX display cable is currently disconnected from the logic board. Thank you for your assitance.

btw…snowwiz search ebay "MacBook Pro A1278 A1342 LCD LED LVDS Cable Connector".

 

[wedgeman]

Has anyone bought the cheaper aftermarket front glass for the 13 inch Macbook or Macbook pro?Just wondering if it fits good & looks original or should I look for original.Can anyone recommend an Ebay seller that sells them.Thanks

Try amazon. Good prices and a far better experience.

I've seen 13" original for $40. Can't imagine plastic being worth the difference.

 

[l.a.rossmann]

Has anyone bought the cheaper aftermarket front glass for the 13 inch Macbook or Macbook pro?Just wondering if it fits good & looks original or should I look for original.Can anyone recommend an Ebay seller that sells them.Thanks

The true and great irony is that aftermarket glass actually costs more than original. Most vendors selling aftermarket are just trying to get rid of old stocks they purchased in high quantities, so that they can get to selling the new, original glass. The difference is that the original glass does not have bubbles in it due to higher quality manufacturing. It also has black border, not grey border. It is impossible to distinguish the two borders unless you have them right next to each other.

 

[Astroboy907]

The true and great irony is that aftermarket glass actually costs more than original. Most vendors selling aftermarket are just trying to get rid of old stocks they purchased in high quantities, so that they can get to selling the new, original glass. The difference is that the original glass does not have bubbles in it due to higher quality manufacturing. It also has black border, not grey border. It is impossible to distinguish the two borders unless you have them right next to each other.

Hmmm.... I think I might have gotten some plexiglass aftermarket.. It scratched pretty easily after I got it, but it fits perfectly

 

[activa]

Repair shops?? BUMP

Bump...

know this thread is a DIY, but I took DIY as far as I could... I soldered a hair-thin wire (to act as a rudimentary fuse) across the open fuse as identified earlier in this thread.

So the question is whether anyone here has the equipment to do the necessary repairs, or (more likely?) whether anyone has used one of the dozen or so shops that advertise on ebay.

ANYONE????

Hi, I have a 2010 17" MBP A1297. Water damage--all seems to work fine except backlight. I soldered a thin wire across the open fuse and now I get a brief flicker at startup sometimes when the machine has been cooled down for a while, but other than that nothing.

My question is whether anyone with this problem has tried any of the numerous ebay services that offer to fix such problems (prices usually range from $200 to $250).

Of course, if anyone recognizes the symptoms and can point me to the exact component AND self-repair is a possibility I'd be eternally grateful.

Or, if anybody here has the pro equipment and wants to make an offer for the repair I'm all ears.

 

[Dadioh]

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...

i change the fuse like in post 182 made by you
https://forums.macrumors.com/threads/972699/

initial i don-t have light...but on external working good...
i repair light change fuse...i put the original display light work and vertical stripes apear...

after that i try another display lg......and i put again original display...only light 27v at backlight voltage point at rezistor 125 but no light..

PLEASE indicate on display conector pins what to measure at all pins they indicate something...

THX

Sorry. Been really really busy and just checking this thread now. So it sounds like you have repaired the backlight but now you have vertical stripes? Sounds like the LVDS connector is not making proper contact on all pins. Carefully reseat the LVDS connector and make sure the latch is fully engaged over the connector. Also make sure the black tape on the latch is centered so that the latch does not short out any of the connections on the connector.

----------

Quote:
Originally Posted by aqibi2000
Dadioh can you please please assist me post Number 606. Thank youuu
Hi. I don't have any experience with the A1342 so I hadn't responded. Also, that model uses a different backlight driver from the aluminum unibodies. But from what you describe that backlight driver is detecting a problem... probably over current, and shutting itself off. You will need to troubleshoot that circuit but I am not the right one to help. Sorry.

My Mac has lost its backlight, and i need to know how to test the WLED Driver circuitry. I have a Amprobe Digital multimeter and Jovy Systems Rework equipment, from which I repair GPU's on a daily basis but not circuitry.

I'm sure somebody out here can help with regards to my A1342 tripping out the backlight; as it down briefly try to power it but cuts out (0.000001 second upon power up). Apart from that works 100%

The fuse shows 12V, but I don't know how to test the other circuity..

This is the best forum I have ever visited. Everyone is so helpful keep it up guys.

Here is schematic : http://ifixit-documents.s3.amazonaws.com/OlSa6sc46JKxNuUO.pdf


Here I did a diode test on the Caps all others showed some form of reading even 0.00, but this one indicated never and showed (O L etc)

[url=http://s16.postimage.org/cxtswhxxt/Slide1.jpg]Image[/url]

This image should help explain, can somebody assist me, or it it invalid conducting a diode test in any way shape or form on a capacitor anyways.

I am not sure if you can use a diode test on a cap and get repeatable results. The diode test is measuring the forward voltage drop across the diode I assume. Capacitors do not pass DC current so not sure you would read anything as a diode.

----------

So, my 15" mid-2009 Macbook Pro (2.8GHz CTO, A1286) suffered a spill. I broke it down, bathed a bunch of components in 99% isopropyl alcohol and cleaned everything I could up, let it dry and now it's booting again. Aside from the keyboard being screwed up (have a replacement on the way), my display is screwy. The backlight does work, however it's only bright at the bottom. The upper 75% of the screen is dark and blotchy. Is this likely just a LCD panel that needs replaced, or potentially something going on with the LED driver on the logic board or LVDS cable? I'm hoping I'll be able to survive this with a straightforward LCD replacement (actually using this as an opportunity to upgrade to the higher-res panel!), but I don't want to do that until I'm sure I understand the backlight and what really is broken.

How does the backlight work, exactly? Is there just one row at the bottom that should diffuse evenly across the entire display? Are there multiple rows?

Attached is what the display looks like. Hoping someone recognizes this type of issue.

I must admit I did stick it in a 170 degree oven (as low as it would go) for a few minutes to warm it up and convince myself things were dry before I turned it on the first time, without the logic board or battery inside. I figured 170 degrees was something these components are able to handle. I think that didn't ruin anything... but it's possible heat damage is also a factor. :-/ Safe to assume some alcohol got up inside the display assembly too.

Looks like the display panel needs to be replaced. The LED's are in a row across the bottom and the internal layers in the deflect or diffuse the light in an even manner. Maybe liquid got into the panel itself. No point mucking about with the WLED driver at this point. It is not the issue.

----------

Thanks Dadioh for help, I just replace the 2A fuse with a dot. i use multimeter DCV 200 Not 200M. The fuse one side is 12.1V other side only 8.7V, and WLED Drive Pin 4 shows 00.1, When I change DCV 20 WLED pin4 show 0.06. do i need to change both. or just replace WLED drive.

You should not see any voltage drop across a fuse. It is very low resistance so you should see 12V on both sides. Otherwise, maybe you replaced the fuse with a resistor by mistake?

----------

Has anyone bought the cheaper aftermarket front glass for the 13 inch Macbook or Macbook pro?Just wondering if it fits good & looks original or should I look for original.Can anyone recommend an Ebay seller that sells them.Thanks

Yes. I have replaced a few of these with no issues. I got a unit once that someone had used a super cheap, obviously plastic replacement and it was horribly marked up and didn't fit right. No idea where they got it and what they paid.

I have bought from a few places and received very good quality replacement glass. Usually paying around $40 to $50.

----------

I have a Macbook 2.26mhz A1342 logic board. The situation is I can see the fan spin and hear the superdrive spin as well as the hard drive, so the logic board is trying to come up. The problem is I can't see anything on the screen. The display, the display cable and logic board display circuitry are all unknowns. I was told that this logic board works, to me it's still an unknown until I can verify that. The display and cable have been through a liquid spill so they are definitely unknowns. My question is using a Mini Displayport cable can I bypass the internal display and have the video output go to external display? If so, are there any special keys or key sequence I need to press to engage the external display? The 30 pin I-PEX display cable is currently disconnected from the logic board. Thank you for your assitance.

btw…snowwiz search ebay "MacBook Pro A1278 A1342 LCD LED LVDS Cable Connector".

The shortcut key to toggle the display between mirrored and extended mode is "command-F1".

----------

Bump...

know this thread is a DIY, but I took DIY as far as I could... I soldered a hair-thin wire (to act as a rudimentary fuse) across the open fuse as identified earlier in this thread.

So the question is whether anyone here has the equipment to do the necessary repairs, or (more likely?) whether anyone has used one of the dozen or so shops that advertise on ebay.

ANYONE????

I haven't used any of the eBay shops since I do all my own repairs but I would suggest reading through their eBay ratings to see what people are saying that have bought their services.

 

[insiderla]

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!

 

[Sold]

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...

i change the fuse like in post 182 made by you
https://forums.macrumors.com/showthre...=972699&page=8

initial i don-t have light...but on external working good...
i repair light change fuse...i put the original display light work and vertical stripes apear...

after that i try another display lg......and i put again original display...only light 27v at backlight voltage point at rezistor 125 but no IMAGE...only a white screenwith no stripes...initial stripe disapear...even on external display NO IMAGE !!!

PLEASE indicate on display conector pins what to measure at all pins they indicate something...

NO LDVS SIGNALS...
what can i do?

 

[2bit]

Dadioh, thank you for your replay...

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.

 

[Astroboy907]

Bump...

know this thread is a DIY, but I took DIY as far as I could... I soldered a hair-thin wire (to act as a rudimentary fuse) across the open fuse as identified earlier in this thread.

So the question is whether anyone here has the equipment to do the necessary repairs, or (more likely?) whether anyone has used one of the dozen or so shops that advertise on ebay.

ANYONE????

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...

----------

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...

i change the fuse like in post 182 made by you
https://forums.macrumors.com/showthre...=972699&page=8

initial i don-t have light...but on external working good...
i repair light change fuse...i put the original display light work and vertical stripes apear...

after that i try another display lg......and i put again original display...only light 27v at backlight voltage point at rezistor 125 but no IMAGE...only a white screenwith no stripes...initial stripe disapear...even on external display NO IMAGE !!!

PLEASE indicate on display conector pins what to measure at all pins they indicate something...

NO LDVS SIGNALS...
what can i do?

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.

 

[applerepairs]

It is Definitely a logic board issue, You need to replace the logic board.