MDS-SP55 - Sony Audio Service Manual (repair manual). Page 9

9

• 0.9 mW power

Specified value : 0.84 to 0.92 mW

• 7.0 mW power

Specified value : 6.8 to 7.2 mW
lop (at 7mW)

• Labeled on the optical pick-up

Iop value ± 10mA

• Traverse waveform

Specified value : Below 10% offset

• Error rate check

Specified value : For points a, b, and c
C1 error : Below 220
AD error : Below 2

• Error rate check

Specified value:
a. When using test disc (MDW-74/GA-1)

C1 error : Below 80
AD error : Below 2

b.When using check disc (TDYS-1)

C1 error : Below 50

• CPLAY error rate check

Specified value:
C1 error : Below 80
AD error : Below 2

• Unsatisfactory if displayed as T=@@ (##) [NG]

NG
(@@, ## are both arbitrary numbers)

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”.

Laser power check
(5-6-2 : See page 24)

Traverse check
(5-6-3 : See page 24)
Focus bias check
(5-6-4 : See page 25)

C PLAY check
(5-6-5 : See page 25)

Self-recording/playback
check
(REC/PLAY)
(5-6-6 : See page 25)

TEMP check
(Temperature
compensation
offset check)
(5-6-1 : See page 24)

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 board)

• Check the signals around IC101, IC121, CN102,

CN103 (BD board)

Measure if unsatisfactory:

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.

The system microprocessor can be reset in the following procedure.
Use these procedure when the unit cannot be operated normally due to the overrunning of the microprocessor, etc.
Procedure :
Remove the short-pin attached to CN821, and power off or del AC cable, and then attach it again. Remove the AC code, and wait for about
five seconds, and turn on the power again, and put the short-pin.