Sony HCD-V5500 - 1 Servicing Note

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SECTION 1
SERVICING NOTE
SELF-DIAGNOSIS
This model has the self-diagnosis function for the VIDEO and
AUDIO decoder sections.
Immediately after the power on, the self-diagnosis function searches
each operation of IC’s around the mechanism control microcomputer
(IC701).
The results can be checked by connecting an oscilloscope to TP709
(LED) of the VIDEO board.
Note: The LED for check (D701) is mounted to some sets
(FORMER TYPE). In this case, confirm the lighting
condition of LED.
[VIDEO BOARD] (SIDE A)
[VIDEO BOARD] (SIDE B)
Oscilloscope (Waveform) Symptom
No error
External SRAM (IC751)
error
MPEG decoder (IC201)
error
DRAM (IC251)
error
H
L
Light
H
L
1 time blinking
H
L
2 time blinking
H
L
3 time blinking
VIDEO board
TP709 (LED)
Oscilloscope
+
_
D701
IC771
TP709 (LED)
X901
IC751
IC251