macbook pro a1286 no image on internal but ok on external

[highpulse]

Well this computer was a working one , but we had here another that the board was with damaged connector , my collegue swapped screen assembly between machines , and he fucked up the good board , that was giving image on both internal and external , i noticed that the board was with some burned pins , so i replaced the socket , but still no image on internal !
the board is a 820-2915-b , so if anyone have this schematic and have certain parts to chek first let me know .

thk in advance

[dellxps15]

Re: macbook pro a1286 no image on internal but ok on external

here is schematic + board view.

edit: post good picture of lvds connector zone.

[polytek]

Re: macbook pro a1286 no image on internal but ok on external

Try this

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

for what i notice , on pins 38 39 and 40 i got 0 ,
i got the enable lcd 2 and 3 pins 3.3 volts
i heard the chime , but no image , but i notice i slight diference on the screen getting more black the screen .
will send the photo in a minute

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

pins 2 and 3 and 38 39 and 40 are bit merged with the solder , but because of ripped solder mask , but they are in same trace , so no problem , about the outher pins , are all well soldered and making good contact

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

PPVOUT_S0_LCDBKLT got really 0 even cheking the coil l9701 , 0 volts ,

[dellxps15]

Re: macbook pro a1286 no image on internal but ok on external

if u put a light can you see image ?
without hard drive wait a bit and you should see a folder with a ? in the middle lower part of lcd.

if yes check backlight little 0402 fuse and backlight ic.

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

backlight IC AKA U9701 ?
litlle bga ?

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

yes there no backlight i got image very deep
the ? folder since i dont have hdd here

[dellxps15]

Re: macbook pro a1286 no image on internal but ok on external

check first F9700 fuse for continuity, if it works or not. you should have 12.5volt both side.

yes u9701 is backlight ic chip. if fuse is ok, check if ic has not burnt.

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

well must be that one since i dont have any voltage on the coil that feed the PPVOUT_S0_LCDBKLT

before cheked that i got VIN on pin C1pad and also PP3V3_S0 got 3.3 on pad C4, confirmed that voltage on the C9711

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

yes was the fuse , i was tring to find this fuse for some good time , and didnt find it , well its always good having some people who are more expert in certain areas thk once again dellxps , 2 apple machine you help me out

cheers mate

[dellxps15]

Re: macbook pro a1286 no image on internal but ok on external

you welcome. for fuse buy 2A fast blow 0402 25 or 32volt. they are on ebay.

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

yeah removed from another board i had here for spares

cheers mate

[highpulse]

Re: macbook pro a1286 no image on internal but ok on external

now im waiting for another socket , and new lvds cable for the outher mac , and then will chek the board to see if the fuse is fucked up as well :__O)

[premanpurimas]

Re: macbook pro a1286 no image on internal but ok on external

thanks for the schematic and brd

[anand797]

Re: macbook pro a1286 no image on internal but ok on external

Thanks guys really helpful post

[kofe]

Re: macbook pro a1286 no image on internal but ok on external

thanks for the schematic

[danielFAB]

Re: macbook pro a1286 no image on internal but ok on external

Thanks!!!!!!!! for the schematic

[Pascal Komlassan]

Re: macbook pro a1286 no image on internal but ok on external

Try this

good