Sony MDS-JE770 Precautions for Checking Laser Diode Emission, Precautions for Adjustments

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MDS-JE770

5-2. PRECAUTIONS FOR CHECKING LASER DIODE EMISSION

To check the emission of the laser diode during adjustments, never view directly from the top as this may lose your eye-sight.

5-3. PRECAUTIONS FOR USE OF OPTICAL PICK- UP (KMS-260B/260E)

As the laser diode in the optical pick-up is easily damaged by static electricity, solder the laser tap of the flexible board when using it. Before disconnecting the connector, desolder first. Before connect- ing the connector, be careful not to remove the solder. Also take adequate measures to prevent damage by static electricity. Handle the flexible board with care as it breaks easily.

pick-up	flexible board

laser tap

Optical pick-up flexible board

5-4. PRECAUTIONS FOR ADJUSTMENTS

1)When replacing the following parts, perform the adjustments and checks with in the order shown in the following table.

2)Set the test mode when performing adjustments. After completing the adjustments, exit the test mode.

Perform the adjustments and checks in “group S” of the test mode.

3)Perform the adjustments to be needed in the order shown.

4)Use the following tools and measuring devices.

•Check Disc (MD) TDYS-1 (Parts No. 4-963-646-01)

•Test Disk (MDW-74/GA-1) (Parts No. 4-229-747-01)

•Laser power meter LPM-8001 (Parts No. J-2501-046-A)

or

MD Laser power meter 8010S (Parts No. J-2501-145-A)

•Oscilloscope (Measure after performing CAL of prove.)

•Digital voltmeter

•Thermometer

•Jig for checking BD board waveform (Parts No. : J-2501-196-A)

5)When observing several signals on the oscilloscope, etc., make sure that VC and ground do not connect inside the oscillo- scope.

(VC and ground will become short-circuited.)

6)Using the above jig enables the waveform to be checked with- out the need to solder.

(Refer to Servicing Note on page 6.)

7)As the disc used will affect the adjustment results, make sure that no dusts nor fingerprints are attached to it.

				Parts to be replaced
Adjustment
Adjustment	Optical	IC101	IC102	IC151	IC190	IC195	D101
	Pick-up	IC101	IC102	IC151	IC190	IC195	D101
	Pick-up

5-7. Initial setting of adjustment values

5-8. Recording of Iop information

5-9. TEMP ADJUST

5-10. Laser power adjustment

5-11. Iop NV Save

5-12. Traverse adjustment

5-13. Focus bias adjustment

5-16. Auto gain adjustment

5-6-4. AUTO CHECK

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Contents MDM-7A Specifications873-890-11 MDS-S50SELF-DIAGNOSIS Function Genera l Power requirementsSupplied accessories MDS-JE770Items of Error History Mode Items and Contents Exploded Views Table of ContentsDisassembly DiagramsFlexible Circuit Board Repairing MDS-JE770 Section Service NotesIOP JIG for Checking BD Board WaveformRecord Precedure Optical PICK-UP Block Type Discrimination KSN-260EChecks Prior to Parts Replacement and Adjustments Forced ResetMain Board Component Side Bit Binary Retry Cause Display ModeBit When Binary Higher Bits Lower Bits Hexa DetailsHexadecimal Binary Button Descriptions MDS-JE770 Section GeneralDisassembly Flow MDS-JE770 Section DisassemblyFront Panel Section Two screws Main BoardOver Light Head HR901, BD Board Mechanism Deck Section MDM-7ALoading Motor Assy M103 Holder AssyOptical PICK-UP Sled Motor Assy M102, SliderSpindle Moter Assy M101 Exiting the Test Mode MDS-JE770 Section Test ModePrecautions for USE of Test Mode Setting the Test ModeSelecting the Test Mode MENU/NO Operating the Continuous Playback ModeFunctions of Other Buttons Test Mode DisplaysMode display Error rate displayInformation When Memory NG is DisplayedMeanings of Other Displays Automatic SELF-DIAGNOSIS FunctionMDS-JE770 Section Electrical Adjustments Parts Replacement and AdjustmentCheck before replacement Auto Gain Control Output Level Adjustment flowTemp Adjust Precautions for Checking Laser Diode EmissionPrecautions for USE of Optical PICK- UP KMS-260B/260E Precautions for AdjustmentsChecks Prior to Repairs Using the Continuously Recorded DiscTraverse Waveform Auto CheckOther Checks Traverse CheckSelf-Recording/playback Check Play Check MO Error Rate CheckCD Error Rate Check Focus Bias CheckInitial Setting of Adjustment Value Temperature Compensation Offset AdjutmentLaser Power Adjustment Iop NV Save Traverse AdjustmentFocus Bias Adjustment MO Auto Gain Control Output Level Adjustment Error Rate CheckAuto Gain Control Output Level Adjustment CD Auto Gain Control Output Level AdjustmentAdjusting Points and Connecting Points Circuit Boards Location MDS-JE770 Section DiagramsMain Board For schematic diagramsFor printed wiring boards BD BoardBlock Diagrams BD Section IC171IC190 Main Section IC360 2/2IC1 2/2 Write Head SemiconductorOVERSemiconductor Optical Pick UP BlockBoard Board Main Main Schematic Diagram Main /2 See page 51 for IC Block Diagrams IC1 Model is printed on diagramHP Board Display BoardKB Board KEY-SW BoardLED Drive Schematic Diagram Display SectionCN921 C924 LF900 C910 RY910C951 C952 D910Main Schematic Diagram Power SectionIC101 CXA2523AR BD Board IC Block DiagramsIC500 AK4524 Main Board IC PIN Function Description IC101 CXA2523AR RF Amplifier BD BoardPin No Pin Name Description Pin No Pin Name Desription Avdd MvciAsyo AsyiFS4 TfdrFfdr FrdrFlck IIC PowerADA.RESET FldtProtect ADA. LatchEPN DINT1/H ClipREC Flcs TimerSTB Beep SWOSC0 ResetVDISP1 VFL1Chassis Section Section Exploded ViewsNot supplied Supplied with J790 FL750 With RV790 FL750 1-517-987-11 Indicator TUBE, FluorescentMechanism MDM-7A Motor ASSY, Loading HEAD, Over LightMotor ASSY, Spindle Motor ASSY, SledMDS-JE770 Section Electrical Parts List Short SwitchMetal Chip Jumper ResistorMDS-JE770 Display HP KB KEY-SW KEY-SW Main MDS-JE770 Main 2SD2144S-TP-UVW Resistor VOL-SEL MDS-JE770 Main PTMemo MDS-JE770 Revision History