Sony MDS-SD1 service manual Checks Prior To Parts Replacement And Adjustments

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	Measure if unsatisfactory:
	(Unsatisfactory if specified value is not satisfied)
Laser power check	• 0.9 mW power	• Clean the optical pick-up
(5-6-2 : See page 25)	Specified value : 0.84 to 0.92 mW	• Adjust again
	• 7.0 mW power	• Replace the optical pick-up
	Specified value : 6.8 to 7.2 mW
	lop (at 7mW)	• Replace the optical pick-up
	• Labeled on the optical pickup
	Iop value ± 10mA
Traverse check	• Traverse waveform	• Replace the optical pick-up
(5-6-3 : See page 25)	Specified value : Below 10% offset
Focus bias check	• Error rate check	• Replace the optical pick-up
(5-6-4 : See page 26)	Specified value : For points a, b, and c
	C1 error : Below 220
	AD error : Below 2
C PLAY check	• Error rate check	• Replace the optical pick-up
(5-6-5 : See page 26)	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/playback	• CPLAY error rate check	If always unsatisfactory:
check	Specified value:	• Replace the overwrite head
(REC/PLAY)	C1 error : Below 80	• Check for disconnection of the circuits around the
(5-6-6 : See page 26)	AD error : Below 2	overwrite head
		If occasionally unsatisfactory:
		• Check if the overwrite head is distorted
		• Check the mechanism around the sled
TEMP check	• Unsatisfactory if displayed as T=@@ (##) [NG]”	• Check for disconnection of the circuits around D101
(Temperature	NG	(BD board)
compensation	(@@, ## are both arbitrary numbers)	• Check the signals around IC101, IC121, CN102,
offset check)		CN103 (BD board)
(5-6-1 : See page 25)

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.

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