MacBook Pro Unibody - No Backlight - Logic Board Question

[Dadioh]

ok made a picture:


1=soldered location by old owner is gives 005 @ ohm 200 setting
2=same kinda capacitor gives no reply at all to multi meter! i also noticed this is the capacitor which is shorted on pictures above (few posts back by other person)

going further on wled to ground now

help?

Regards, Peter

OK. So just to make sure I understand... Are all of the purple lines you drew on the WLED driver measuring 005 ohms? There should only be a few points measuring shorts to ground.

What is the 200ohm circle you drew?

Also, I am not sure what the fuse you labeled as "2" is. Fuse "1" is the fuse that feeds the WLED driver I believe. Unfortunately I don't have a logic board of your particular vintage to check for myself.

edit: Just looked closer at the picture. Typically components with the "dot" on the top are fuses but you indicated that one of them is a cap? I wish I had one of these boards so I could walk you through it but I need to just go by pictures unfortunately :-(


Peter. Can you enable PM or email on your account so that I can send you an email? I have something that might help....

 

[Poeter]

No forget that i die that wrong, they measure 005 form wled pin ten follow track to next point. I saw later that it needed to be wled pin to ground instead to next point. I still need to check them all again.

The ohm thing was just what settings i used, i have 2 digital multimeters and a lot of knowledge on mobile phones repair, so i am technical but not on this level but i dan learn.

Fuse 1 is on the board most top and already soldered by former owner i guess.

Fuse 2 looks like the same and i just saw it and thought let's measure it aswell.
It gives no respons at all.

I have motherboard of this model for you of you want, but with liquid damage.

I will enable PM.

Regards, Peter

 

[ssanders1970]

After cleaning up my macbook pro from water damage and testing all the components I found that everything is ok except for pins 21 and 22 on the board which are completely gone. Is there any way to bypass those pins from the connector?

 

[Dadioh]

After cleaning up my macbook pro from water damage and testing all the components I found that everything is ok except for pins 21 and 22 on the board which are completely gone. Is there any way to bypass those pins from the connector?

I have had this before. Sometimes it also eats away at the tracks on the circuit board. I fix them by replacing the connector with a new one and bridging solder if required to get contact on the logic board. I think the connectors are made by I-PEX. Replacing them takes a bit of soldering skill and the right tools (microscope, good iron).

 

[ssanders1970]

I have had this before. Sometimes it also eats away at the tracks on the circuit board. I fix them by replacing the connector with a new one and bridging solder if required to get contact on the logic board. I think the connectors are made by I-PEX. Replacing them takes a bit of soldering skill and the right tools (microscope, good iron).

It appears that there's nothing to solder it to.

 

[mf-fpal]

macbook white model-A1181 y2007

hi
a have macbook but cant turn on. i need logic board schematics diagram.
please help

 

[ssanders1970]

Ok, so I verified that the pad isn't pulled off. I have my 27v, and in checking it, I must have made contact with the busted pins because the LED lit right up. Considering the fact that I don't have a microscope, does anyone know a place that I could send it to have a new I-pex connector put on? Is there anyone here that has done it before that would like to tackle this little project?

 

[granosx]

Hey Dadioh! Very nice thread, I have read as much as I could. I was hoping you could guide me in the right direction,

I have a Macbook Pro mid 2009 model 13.3 inches 2.53ghz core 2 duo / 4gb ram model.

The problem with this pro, is that at first it would turn on no prob, everything works, keyboard , keyboard backlight, charger etc.. but the lcd backlight was dead. In other words I could see and use it etc.. but it is VERY dark. So I followed what others have said ( measure resistance etc.. ).

Next time I turned on the laptop, the fuse flashed and looked like it popped essentially. Now the fuse isn't even there and my pro does not turn on. I am hoping this doesn't mean the pro logic board is dead, as I had ordered 2 fuses ( just in case I mess 1 up ) and should arrive today or tomorrow. I believe that when the fuse burned up, it might have made an open circuit and the circuit isn't complete, causing the laptop to no longer turn on. Do you think if I solder a new fuse it may work? I tried plugging the battery in again and it starts to smell like burning/ sometimes it sparks, so I have since disconnected the battery.

Here are some pictures:

Correct me If I am wrong, I am studying EE but I only know a little bit so far, have a quiz today on Transistor and MOSFET dc/ac small signal analysis.

PS: If you have an idea, maybe I can pay you a fee to do the soldering for me or whatever is necessary, but first I will check if someone at my university has the tools needed.

 

[Dadioh]

hi
a have macbook but cant turn on. i need logic board schematics diagram.
please help

PM me and I can point you to some resources.

----------

Hey Dadioh! Very nice thread, I have read as much as I could. I was hoping you could guide me in the right direction,

I have a Macbook Pro mid 2009 model 13.3 inches 2.53ghz core 2 duo / 4gb ram model.

The problem with this pro, is that at first it would turn on no prob, everything works, keyboard , keyboard backlight, charger etc.. but the lcd backlight was dead. In other words I could see and use it etc.. but it is VERY dark. So I followed what others have said ( measure resistance etc.. ).

Next time I turned on the laptop, the fuse flashed and looked like it popped essentially. Now the fuse isn't even there and my pro does not turn on. I am hoping this doesn't mean the pro logic board is dead, as I had ordered 2 fuses ( just in case I mess 1 up ) and should arrive today or tomorrow. I believe that when the fuse burned up, it might have made an open circuit and the circuit isn't complete, causing the laptop to no longer turn on. Do you think if I solder a new fuse it may work? I tried plugging the battery in again and it starts to smell like burning/ sometimes it sparks, so I have since disconnected the battery.

Here are some pictures:


Correct me If I am wrong, I am studying EE but I only know a little bit so far, have a quiz today on Transistor and MOSFET dc/ac small signal analysis.

PS: If you have an idea, maybe I can pay you a fee to do the soldering for me or whatever is necessary, but first I will check if someone at my university has the tools needed.

Burning smell / Sparking = BAD

The backlight fuse only powers the backlight circuit. Your Macbook should boot up fine even if it open circuit so something else has happened.

Do you remember where the sparking was? It may sound funny but often you can use your nose to locate the location of the burning smell. I would avoid applying power again until you have determined the source. You will just do more damage.

 

[Dadioh]

Ok, so I verified that the pad isn't pulled off. I have my 27v, and in checking it, I must have made contact with the busted pins because the LED lit right up. Considering the fact that I don't have a microscope, does anyone know a place that I could send it to have a new I-pex connector put on? Is there anyone here that has done it before that would like to tackle this little project?

Well that is good news. Under a microscope you could probably use an exacto knife to scrape off the solder resist to expose copper beneath and have something to solder to. If you can hold up the board on a bit if an angle under a microscope you could view where the pins come out of the back of the connector and attach to the board. If there is enough pin left you "might" be able to get solder to attach to it but the plastic is very heat sensitive so it may not survive the attempt.

The 30pin connector used on the 13" models is 20474-030E-11 so some googling might identify a place that carries them. Example below from a quick Google search. Not endorsing it....

http://www.displaycableconnectors.com/self-adhesive-vinyl-grey.html

 

[ssanders1970]

Well that is good news. Under a microscope you could probably use an exacto knife to scrape off the solder resist to expose copper beneath and have something to solder to. If you can hold up the board on a bit if an angle under a microscope you could view where the pins come out of the back of the connector and attach to the board. If there is enough pin left you "might" be able to get solder to attach to it but the plastic is very heat sensitive so it may not survive the attempt.

The 30pin connector used on the 13" models is 20474-030E-11 so some googling might identify a place that carries them. Example below from a quick Google search. Not endorsing it....

http://www.displaycableconnectors.com/self-adhesive-vinyl-grey.html

Well there wasn't enough pin left so it looks like a new connector. What kind of microscope and soldering iron do you recommend?

 

[Dadioh]

Well there wasn't enough pin left so it looks like a new connector. What kind of microscope and soldering iron do you recommend?

The microscope I use is shown below. I am quite pleased with the quality of construction and features.

http://www.ebay.ca/itm/170704732757...X:IT&_trksid=p3984.m1423.l2649#ht_4032wt_1219

As far as a soldering iron goes I also have the unit shown below which features both hot air tool as well as soldering iron.

http://www.ebay.ca/itm/150721080422...X:IT&_trksid=p3984.m1438.l2649#ht_4238wt_1219

It is OK for casual soldering. For most of my soldering I use a Metcal SP-200 system. Very pricey but an excellent system.

http://www.okinternational.com/product_soldering/sp200

So I am not really sure if you want to be investing this much in soldering unless it is something you plan to do on a regular basis. You might be better off finding out if there is someone local who can do it for you at a reasonable price. Do you live in a major urban centre? If so there might be a possibility of finding someone on Craiglist or Kijiji. There also seem to be quite a few shops on eBay offering logic board repair but they seem to charge an awful lot.

If you are really stuck send me a PM.

 

[wedgeman]

thanks for the info on the connector! very cool!!

 

[PJonHar]

WLED driver

I have a MacBook Pro 15" late 2008. The WLED driver has APP001 on it. People say you can not get these can they be replaced with the LP8543 or LP8545?

The LVDS connector had burnt out on pins 38,39 & 40, I have bypassed these via attaching wires to the capacitors C9709 and C9710. The 2A fuse did blow currently trying to find one to attach.

Any information is grateful.

 

[dfh88]

The fuse proceeds through a FET to the WLED driver (probably the 6 pin package you mention). The FET can handle a fair bit of current so I would suspect something else further downstream. Most likely the WLED driver. A boundary scan around the WLED driver measuring each pin resistance to ground would be the next step that I would take. Post the readings back here.

Hi Dadioh, here are the readings from the APP001

(i assume pin 1 is top left, going anti clockwise)

1 o/c
2 9.9k
3 15k
4 47k
5 30k

6 1m
7 100
8 320k
9 47k
10 96k

11 100k
12 2m
13 50k
14 70k
15 o/c

16 o/c
17 o/c
18 0.1
19 o/c
20 3m

the motherboard connector is ok, i bought a new cable and no more shorts, but no backlight, do you think i killed the APP001?

 

[Dadioh]

I have a MacBook Pro 15" late 2008. The WLED driver has APP001 on it. People say you can not get these can they be replaced with the LP8543 or LP8545?

The LVDS connector had burnt out on pins 38,39 & 40, I have bypassed these via attaching wires to the capacitors C9709 and C9710. The 2A fuse did blow currently trying to find one to attach.

Any information is grateful.

They are not compatible unfortunately. LP8543 is 28 pin and APP001 is 24 pin for starters. They are completely different devices

Only way that I know is to scavenge an APP001 from a donor board.

Pins 38, 39, 40 are the pins that carry the backlight voltage to the screen. In liquid spills they often corrode or burn out. Might be easier to replace the LVDS connector than to try and bypass.

----------

Hi Dadioh, here are the readings from the APP001

(i assume pin 1 is top left, going anti clockwise)

1 o/c
2 9.9k
3 15k
4 47k
5 30k

6 1m
7 100
8 320k
9 47k
10 96k

11 100k
12 2m
13 50k
14 70k
15 o/c

16 o/c
17 o/c
18 0.1
19 o/c
20 3m

the motherboard connector is ok, i bought a new cable and no more shorts, but no backlight, do you think i killed the APP001?

I think I may have posted some typical resistances earlier in the post. I am not near my workbench at the moment which is where I have marked down the typical resistances. While you are waiting for me have a look and see if anything stands out.

 

[dfh88]

They are not compatible unfortunately. LP8543 is 28 pin and APP001 is 24 pin for starters. They are completely different devices

Only way that I know is to scavenge an APP001 from a donor board.

Pins 38, 39, 40 are the pins that carry the backlight voltage to the screen. In liquid spills they often corrode or burn out. Might be easier to replace the LVDS connector than to try and bypass.

----------



I think I may have posted some typical resistances earlier in the post. I am not near my workbench at the moment which is where I have marked down the typical resistances. While you are waiting for me have a look and see if anything stands out.

I found your values but they look different to mine.

i traced where on the board the led wiring comes to:

are these green things fuses?

the top two measure .4 ohms but the lower one is o/c

 

[dfh88]

success! the green things are additional fuses.
for now i replaced it with a 1a glass fuse with leads soldered on, taped next to the fan.

so mine blew due to the clip that holds the screen cable shorting on the back of the connector, the new one came better insulated:

Dadioh thanks for your help, another macbook saved

 

[PJonHar]

success! the green things are additional fuses.
for now i replaced it with a 1a glass fuse with leads soldered on, taped next to the fan.



so mine blew due to the clip that holds the screen cable shorting on the back of the connector, the new one came better insulated:


Dadioh thanks for your help, another macbook saved

Which fuse did you replace with the 1A glass fuse, the green ones or the F9800 (white dot)?

Thanks.

 

[dfh88]

Which fuse did you replace with the 1A glass fuse, the green ones or the F9800 (white dot)?

Thanks.

Just the lower green one, my white dot is still bridged with solder. I want to replace both with smd ones but not sure of the ratings.

 

[PJonHar]

Just the lower green one, my white dot is still bridged with solder. I want to replace both with smd ones but not sure of the ratings.

That 'fuse' you replaced says it is a resistor on the schematics. see attached image. Also the Fuse with the white dot F9800 is a 2A fuse.

 

[PJonHar]

Screen Side Schematics

I have the schematics for the logic board side. Is it possible to get the Screen side schematics?

Also,

@ dfh88 how easy was it to remove your screen? did the glass come off okay?

 

[granosx]

Re:

Hey Dadioh, here is a better pic of the burn in fuse area

I took it to a technician with replacement fuse, but I am having a feeling the motherboard is beyond repair. They are supposed to be multi-layered, so it is very possible that it burned internal items.

What do you think? Tech said he will try to "fill" the hole and place the new fuse.

 

[dfh88]

I have the schematics for the logic board side. Is it possible to get the Screen side schematics?

Also,

@ dfh88 how easy was it to remove your screen? did the glass come off okay?

Dadioh posted the cable pinout did you see that? the cable crosses over at the screen end.

is the green thing a fusible resistor? 0.1ohm? i checked another glass fuse it measures about 0.2ohm, maybe this why it works, or maybe no resistor is actually needed.

i broke the screen front, had it partially off, i didn't know it was glass till it cracked. i think it might come off with plenty of heat from a heat gun/hardryer. new glass ones are on ebay, some sellers have plastic ones. i thought about replacing it with the bezel from a matt version instead, screen seems fine without it - just a normal glossy screen underneath i think.

 

[PJonHar]

Dadioh posted the cable pinout did you see that? the cable crosses over at the screen end.

is the green thing a fusible resistor? 0.1ohm? i checked another glass fuse it measures about 0.2ohm, maybe this why it works, or maybe no resistor is actually needed.

i broke the screen front, had it partially off, i didn't know it was glass till it cracked. i think it might come off with plenty of heat from a heat gun/hardryer. new glass ones are on ebay, some sellers have plastic ones. i thought about replacing it with the bezel from a matt version instead, screen seems fine without it - just a normal glossy screen underneath i think.

I haven't seen the pin out posted for the 15". I had another go yesterday, replaced the 2A fuse but no joy still no backlight. I was thinking of connecting an external supple of 18-27V to pins 38-40 to see if the led's war at least working. this way i could figure out if it is logic board side or screen side.

any thoughts?