Failure Judgement Of The Pickup Assy - Pioneer CDJ-2000NXS Service Manual

5

5.2 FAILURE JUDGEMENT OF THE PICKUP ASSY

This unit has self-diagnostic functions for the drives.
For drive-related malfunctions, first perform the self-diagnostics to check the drives in Service mode. If the results indicate any
problem with the drives, check the following items:
LD power after passing through the objective lens [mW]
SPEC: DVD 0.180 ± 0.03
CD 0.210 ± 0.03
Check method: Measure the LD power, using an optical power meter.
Failure judgment: A value out of the range of the specifications is judged as failure.
LD current [mA]
SPEC: DVD TYP50 MAX70
CD TYP65 MAX75
Check method
Measure the voltage at the probe pad on the SRVB Assy (see the photo below), using a tester.
∗ To check lighting of each LD, follow the procedure indicated in "[7] Checking the servo operations of the drive unit" in
"6.1 SERVICE MODE."
∗ Note that the LD may be degraded if the probes of a tester are applied to or pulled away from the probe pad with the LD ON.
Procedures
1. With the LD OFF, apply the probes of a tester to the reference probe pad (LDCHK) and 78CHK (CD side) or 65CHK
(DVD side).
2. With the probes kept applied to the above-mentioned pads, turn the LD ON to measure the voltage between them.
3. After measurement, turn the LD OFF (ALL OFF) then pull the probes away.
4. Calculate the current value by dividing the measured voltage value by the resistance value mentioned below.
(For CDs: R7008 = 22 ohms, For DVDs: R7007 = 12 ohms)
Failure judgment:
If the calculated current value exceeds the maximum value, the LD has been degraded
IC7002
Fig.1 SRVB Assy
Actuator resistance value [ohms]
Specifications on the focus side: 3.7 ±0.55
Specifications on the tracking side: 4.3 ±0.65
Check method
Directly measure the resistance value of the actuator, using a tester.
* Before measuring, short-circuit the LD short-circuit pads.
Note that the LD may be degraded if connection/disconnection of CN7001 is performed with the LD short-circuit pads open.
• Focus side
Disconnect* the FFC connected to the CN7001 then measure the resistance value between FFC pins 23 and 24.
• Tracking side
Disconnect* the FFC connected to the CN7001 then measure the resistance value between FFC pins 21 and 22.
Failure judgment:
A value out of the range of the specifications is judged as failure.
5
6
78CHK
65CHK
LDCHK
CDJ-2000NXS
6
7
7
8
A
B
C
D
E
F
17
8