Sony 4-216-840-0 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
(6-2 : See page 23)	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
(6-3 : See page 23)	Specified value : Below 10% offset
Focus bias check	• Error rate check		• Replace the optical pick-up
(6-4 : See page 24)	Specified value : For points a, b, and c
	C1 error : About 200
	AD error : Above 00
C PLAY check	• Error rate check		• Replace the optical pick-up
(6-5 : See page 24)	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
(6-6 : See page 24)	C1 error : Below 80		• Check for disconnection of the circuits around the
	AD error : Below 2		overwrite head
			If occasionally unsatisfactory:
			• Check if the overwrite head is distorted
			• Check the mechanism around the sled
Temperature	• Unsatisfactory if displayed as T=@@ (##) [NG”		• Check for disconnection of the circuits around
	NG		D101 (BD board)
compensation
	(@@, ## are both arbitrary numbers)		• Check the signals around IC101, IC121, CN102,
offset check
			CN103 (BD board)
(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.

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