Service Note - Sony HCD-VX77 Service Manual

1 Cut the eleven melted-connection points with a cutting plier.
SELF-DIAGNOSIS
This model has the self-diagnosis function for the VIDEO and AUDIO decoder sections.
Connecting to the LED between TP522 and TP523 on the VIDEO BOARD.
Immediately after the power on, the self-diagnosis function searches each operation of IC's around the mechanism control microcomputer
(IC701). and TP5
The results can be checked by LED of the VIDEO board.
Oscilloscope (Waveform)
Light
2 time blinking
3 time blinking
4
SECTION 1

SERVICE NOTE

2 Panel board
Symptom
H
No error
L
H
MPEG decoder (IC505)
error
L
H
MPEG decoder (IC505)
or
L
DRAM (IC507) error
Note for installing the panel board
Hot melt
Screw hole
Attach the panel board with
six screws (+BVTP 2.6 × 8 )
after the board is removed once.
Do not tighten the screws excessively.
[VIDEO BOARD] (SIDE A)
TP523 TP522
LED
100 91
1 90
IC505
32 65
33 64