Servicing Note - Sony HCD-V5500 Service Manual

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.
Oscilloscope (Waveform)
Light
1 time blinking
2 time blinking
3 time blinking
SECTION 1

SERVICING NOTE

Symptom
H
No error
L
H
External SRAM (IC751)
L error
H
MPEG decoder (IC201)
L
error
H
DRAM (IC251)
error
L
— 3 —
VIDEO board
TP709 (LED)
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)
D701
IC771
[VIDEO BOARD] (SIDE B)
X901
TP709 (LED)
IC751
IC251
Oscilloscope
+
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