[SOLVED]820-3115-B black screen

Bohmmen

New member
have a strange problem with this board. it boots as it should but the screen is black. If I unplug the lcd cable and then plug it in again it works until I turn it off. next time I start it up the black screen is back again.
what can cause this shit?
 

Bohmmen

New member
pin: 8, 9, 11,12, 14, 15, 17, 18 all measures 0,440.
checked my other MBP with the same working board and it measures 0,359 at all pins
 

Bohmmen

New member
If I disconnect battery and magsafe and do SMC reset? by holding down power button 5 sec and then plug in magsafe while still holding down power the screen works. then I can turn it off with power button and on again and it still works, and fan is spinning high. But when I disconnect magsafe an connect it again screen is black again unless I don't disconnect lcd cable.
 

Bohmmen

New member
Tried lcd number seven now and it works! Don't know why because all the other lcd I tried works.
Close this thread
 

Bohmmen

New member
I measured the probe points around U9701 and compared it to a working board and there are some differences. For some reason the pins are numbered on the boardwiev from 1 to 25 but on the schematic its letters and numbers? B4, E3????

First measure is good board.
Volt

Pin 3: 3,12 / 3,12
Pin 5: 24 / 26,8
Pin 6: 12,53 / 12,53
Pin 7: 12,53 / 12,53
Pin 8: 1,24 / 1,24
Pin 9: 0 / 0
Pin 12: 0,015 / 0,015
Pin 13: 0 / 0
Pin 15: 3,1 / 0,57
Pin 17: 0 / 0
Pin 18: 3,3 / 3,3
Pin 19: 3,3 / 3,3
Pin 20: 3,1 / 0,57
Pin 23: 3,1 / 0,8
pin 25: 3,1 / 0,63

The ones that is to low is BKL_ISNS (1-6)
 
Last edited:

Bohmmen

New member
Just discovered that the fu€%€&ing battery sensor was liquid damaged. Changed it and now it seems to work!!!
 
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