Method For Diagnosing Degradation Of The Lds On The Pickup Assy - Pioneer DV-300-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 R2321 or R2323 on the DVDM
Assy. If the voltage is 0.4 V or higher, the 650-nm LD is degraded.
No playback of a CD :
Measure the voltage between the two ends of R2320 or R2322 on the DVDM
Assy. If the voltage is 0.4 V or higher, the 780-nm LD is degraded.
C2301
CP2303
W806
IC2301
R2329
R2319
C2317_1
W802
R2316
5
6
CP2301
Q2307 Q2306
Q2302
C4094
Q2301
Q2304
4006
R2322
C4096
R2311
R4009
R4010
6
7
If the measurements show degradation
of an LD, replace the PICKUP Assy.
DVD MT PCB ASSY
Front side
DV-300-K
7
8
SIDE A
8
A
B
C
D
E
F
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