Sony MDS-M100 Service Manual page 8

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 "5 Electrical Adjustments".
Criteria for Determination
(Unsatisfactory if specified value is not satisfied)
Laser power check • 0.9 mW power
(6-2 : See page 23)
• 7.0 mW power
• Labeled on the optical pickup
Traverse check • Traverse waveform
(6-3 : See page 23)
Focus bias check • Error rate check
(6-4 : See page 24)
C PLAY check • Error rate check
(6-5 : See page 24)
Self-recording/playback • CPLAY error rate check
check
(6-6 : See page 24)
• Unsatisfactory if displayed as T=@@ (##) [NG"
Temperature
compensation
offset check
(6-1 : See page 23)
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.
Specified value : 0.84 to 0.92 mW
Specified value : 6.8 to 7.2 mW
lop (at 7mW)
Iop value ± 10mA
Specified value : Below 10% offset
Specified value : For points a, b, and c
C1 error : About 200
AD error : Above 00
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
Specified value:
C1 error : Below 80
AD error : Below 2
NG
(@@, ## are both arbitrary numbers)
• 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 board)
• Check the signals around IC101, IC121, CN102,
CN103 (BD board)
– 8 –
Measure if unsatisfactory: