Method For Diagnosing Degradation Of The Lds On The Pickup Assy - Pioneer DV-120-K Service Manual

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

Case when this diagnosis is required :
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 NR2301 on the DVD MT PCB Assy.
If the voltage is 0.17 V or higher, the 650-nm LD is degraded.
No playback of a CD :
Measure the voltage between the two ends of NR2301 on the DVD MT PCB Assy.
If the voltage is 0.20 V or higher, the 780-nm LD is degraded.
C8057
R8049
8003
for CD laser diode
NR2301
R8059
C8056
Q8013
Q2302
R2308
Q
5
6
for DVD laser diode
Q2303
CP2301
DV-120-K
6
7
If the measurements show degradation
of an LD, replace the PICKUP Assy.
DVD MT PCB ASSY
CP4003
SH4000
R8035
B8004
C8036
IC7303 IC7301
W845
C7301
W817
C7303
W857
W858
W818
C7315
IC7302
C4010
R4008
CP7301
W815
R8063 C8057
C8067 R8049
Q8020
IC8003
R8076
R8079
R8084
Q8019
NR2301
C8069 R8059
R8067
C8056
Q8018
R8080
Q8013
Q8014
R8085
R8083
Q8021
Q2303
Q2302
C8074
W840
R2308
CP2301
Q2301
SIDE A
7
8
A
B
C
IC4005
IC4003
C4049
IC4004
C4134
97 65
R4047
IC4001
R4053 R4004
R4054
33
1 C4002
D
D4002
W809
R4024
R4063
X4001
R2319
C2307 C2305
R4015
W802
R4016
IC2301
DMJ113A
E
F
23
8