Sony PMC-MD55 Service Manual page 114

CHECKS PRIOR TO PARTS REPLACEMENT AND ADJUSTMENTS (for MD Section)
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
(6-1 : See page 23)
Focus bias check
(6-2 : See page 23)
C PLAY check
(6-3 : See page 23)
Self-recording/playback
check
(6-4 : 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.
NOTE ON MOUNTING PULLY
• 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 7mW)
• Labeled on the optical pickup
IOP value ± 10%
• Error rate check
Specified value :
a. For points A and B
C1 error : About 200
ADER : Below 2
b. For point C
C1 error : Below 50
ADER : Below 2
• Error rate check
Specified value :
a. When using test disc (MDW-74/AU-1)
C1 error : Below 80
ADER : Below 2
b. When using check disc (TDYS-1)
C1 error : Below 50
• CPLAY error rate check
Specified value :
C1 error : Below 80
ADER : Below 2
pulley
DC motor (CD lid open/close)
• 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
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
Press fit pulley to motor with jig.
– 5 –
Measure if unsatisfactory:
2.5 mm