13
CHECKS PRIOR TO PARTS REPLACEMENT AND ADJUSTMENTS IN MD
Before performing repairs, perform the following checks to determine the faulty locations up to a certain extent.
Details of the procedures are described in “5 Electrical Adjustments”.
• 0.9 mW power
Specified value : 0.84 to 0.92 mW
• 7.0 mW power
Specified value : 6.8 to 7.2 mW
Iop (at 8.4mW)
• Labeled on the optical pick-up
Iop value ± 10mA
• Traverse waveform
Specified value : Below 10% offset
• Error rate check
Specified value : For points A and B
C1 error : About 200
AD error : below 2
For point C
C1 error: 20
AD error: below 2
• Error rate check
Specified value:
a.
When using test disc (MDW-74/GA-1)
C1 error : Below 20
AD error : 00
b.
When using check disc (TDYS-1)
C1 error : Below 20
• CPLAY error rate check
Specified value:
C1 error : Below 20
AD error : Below 2
• Unsatisfactory if displayed as T=@@ (##) [NG]”
NG
(@@, ## are both arbitrary numbers)
Laser power check
(6-2 : See page 40)
Traverse check
(6-6 : See page 41)
Focus bias check
(6-7 : See page 42)
C PLAY check
(6-8 : See page 42)
Self-recording/playback
check
(6-9 : See page 42)
Temperature
compensation
offset check
(6-1 : See page 40)
Criteria for Determination
(Unsatisfactory if specified value is not satisfied)
• Clean the optical pick-up
• Adjust again
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
If always unsatisfactory:
• Replace the overwrite head
• Check for disconnection of the circuits around the
overwrite head
If occasionally unsatisfactory:
• Check if the overwrite head is distorted
• Check the mechanism around the sled
• Check for disconnection of the circuits around
D101 (BD (MD) board)
• Check the signals around IC101, IC151, CN102,
CN103 (BD (MD) board)
Measure if unsatisfactory
Note:
The criteria for determination above is intended merely to determine if satisfactory or not, and does not serve as the specified value for adjustments.
When performing adjustments, use the specified values for adjustments.
