Method For Diagnosing Degradation Of The Lds On The Pickup Assy - Pioneer DV-373-S Service Manual

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7.1.6 METHOD FOR DIAGNOSING DEGRADATION OF THE LDS ON THE PICKUP ASSY

Case when this diagnosis is required :
A
When playback of any disc, including a test disc (DVD: GGV1025, CD: STD-905), cannot be performed
How to diagnose
In the case mentioned above, degradation of the laser diodes (LDs) mounted on the PICKUP Assy is suspected.
Measure the voltage between the two ends of one of the resistors mentioned below.
No playback of a DVD :
Measure the voltage between the two ends of R22 or R25 on the DVDM Assy.
If the voltage is 0.4 V or higher, the 650-nm LD is degraded.
B
No playback of a CD :
Measure the voltage between the two ends of R21 or R26 on the DVDM Assy.
If the voltage is 0.4 V or higher, the 780-nm LD is degraded.
C
D P
12
D
1 CN102
C6
R115
R116
R117
R118
R119
R120
C102
E
F
54
1
2
PICKUP ASSY
CN101
PC
C232
CN101
CN104
1
2
24
23 1
4
C233
C230
R25 R25
Q5
R21 R21
R22 R22
R18
C113
C112
R14 R15
R103
C114
R27
R28
2
3
FC
R422
C420
4
5
IC402
C402
Front side
DV-373-S
3
4
If the measurements show degradation
of an LD, replace the PICKUP Assy.
B
DVDM ASSY
SIDE A
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