Brother PR655 Service Manual page 260

Failure Investigation for Electronic Parts
Is the backlight lead properly connected to
connector CN8 on the panel PCB and
connector CN1 on the backlight drive PCB?
Is the resistance between each pin at both ends
1 or below when the backlight lead is removed
from the panel PCB and the backlight drive PCB?
Does the machine function normally when the
backlight drive PCB is replaced with a reliable one?
Is the LCD's FPC properly connected to
connector on the backlight drive PCB?
Is the FFC for the LCD properly connected to connector
CN6 on the panel PCB and the LCD's connector?
Does the machine function normally when the
FFC for the LCD is replaced with a reliable one?
The power is not turned on.
From the previous page
Y
Y
N
Y
Y
N
Change the LCD module.
5 - 5
N
Connect it properly.
N
Change the lead wire assy:
X2 PR-E LED BL.
Y
Change the backlight drive PCB.
N
Connect it properly.
N
Connect it properly.
Y
Change the FFC for the LCD.