Having the following problem, and need help:
Subject: 12' Powerbook G4 867MHZ
Problem: the Backlight is not working. Everything else is working perfect. On startup you can see very slightly the content on the screen, so LCD is not broken. I also exchanged the Inverter, and its fine. I ran a check probing the Pins to the Inverter, and found the following...
there is this socket on the Logic Board, which connects to the Inverter, and has following Pins.
1 - RED +12V Supply for LCD
2 - BLACK 0V REF GROUND
3 - YELLOW +5V SUPPLY
4- GREEN 0V AT ZERO BRIGHTNESS AND +3.2V AT 100% BRIGHTNESS (CONTROL LINE).
Probing this all things are correct, but Pin 1 fails. There is no 12V output on this one. I checked the Fuse F1, but it seems okey. On both sides on F1 Probing reads 12 V
So what could be the Cause, that the 12 Volts from the F1 does not appear on Pin 1 of the Inverter Socket ??
The PB Was Dropped, and the Problem appeared right after the Drop. But since everything else works fine, I think its worth trying to repair the PB.
I do not have a Circuitplan of the PB, so I dont know where to search. Can annyone support me with some help to this problem...
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