CHECKS PRIOR TO PARTS REPLACEMENT AND ADJUSTMENTS
Before performing repairs, perform the following checks to determine the faulty locations up to a certain extent.
Details of the procedures are described in O5 Electrical Adjustments�.
Criteria for Determination
(Unsatisfactory if specified value is not satisfied)Measure if unsatisfactory:
Laser power check Y 0.9 mW powerY Clean the optical pick-up
(5-6-2 : See page 32)Specified value : 0.84 to 0.92 mWY Adjust again
Y 7.0 mW powerY Replace the optical pick-up
Specified value : 6.8 to 7.2 mW
lop (at 7mW)Y Replace the optical pick-up
Y Labeled on the optical pickup
Iop value ? 10mA
Traverse checkY Traverse waveformY Replace the optical pick-up
(5-6-3 : See page 32)Specified value : Below 10% offset
Focus bias checkY Error rate checkY Replace the optical pick-up
(5-6-4 : See page 33)Specified value : For points A, B
C1 error : About 200
AD error : Below 2
For point C
C1 error : Below 50
AD error : Below 2
C PLAY checkY Error rate checkY Replace the optical pick-up
(5-6-5 : See page 33)Specified value:
a. When using test disc (MDW-74/AU-1)
C1 error : Below 80
AD error : Below 2
b. When using check disc (TDYS-1)
C1 error : Below 50
Self-recording/playbackY CPLAY error rate checkIf always unsatisfactory:
checkSpecified value:Y Replace the overwrite head
(5-6-6 : See page 33)C1 error : Below 80Y Check for disconnection of the circuits around the
AD error : Below 2overwrite head
If occasionally unsatisfactory:
Y Check if the overwrite head is distorted
Y Check the mechanism around the sled
TemperatureY Unsatisfactory if displayed as T=@@ (##) [NG�Y Check for disconnection of the circuits around
compensationNGD101 (BD (MD) board)
offset check(@@, ## are both arbitrary numbers)Y Check the signals around IC101, IC121, CN102,
(5-6-1 : See page 32)CN103 (BD (MD) board)
Note:
The criteria for determination above is intended merely to determine if satisfactord vy or not, and does not servalue for adjustments.e as the specifie
When performing adjustments, use the specified values for adjustments.
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ACEC
