Adjustment Procedures - C.E.C. 530CD Service Manual

ADJUSTMENT PROCEDURES
PRECAUTIONS REGARDING ADJUSTMENT REQUIRED EQUIPMENTS
e@ Adjustment is performed in the indicated order. DC Voltmeter
Dualtrace Oscilloscope
@ When adjustment is made for one item, check the other Frequency Counter
items which follow. Signal Generator
Plastic Screwdriver
Diffraction Grating Adjustment Jig
Test Disc (SONY: YEDS4)
@ The laser pick-up has already been precisely adjusted. Do
not touch its mounting screws or controls.
CHECKING FOCUS ERROR SIGNAL
Checking the focus error signal of the pick-up allows for an
evaluation of the pick-up. Be sure this is carried out before
repair.
1. Turnon the power and set the unit to the STOP mode.
2. Connect an oscilloscope between test pin FE of connector
3. Connect the +10V supply voltage to test pin FOFF of
@ When the diffraction grid is adjusted, remove the connector CN7 through a 47kQ. resistor.
mechanism. It is convenient to place an insulating panel on
top of the chassis, and then to place the mechanism on top
of this. (The wires are connected.)
47kO
+10V ——C———» FOFF
Insulator Board
(wood, plastic, etc.)
4. Press the OPEN/CLOSE button and place the test disk
YEDS4 on the table load. Press the OPEN/CLOSE button
again.
5. The waveform shown below is displayed six times on the
oscilloscope when the table load closes. Check that the p-p
voltage is about 8V and that the top and bottom of the
waveform are symmetrical.
Repeated six times
| ©
eer e----@ ---4-4$-------------------}-
Oo
@ Refer to the adjustment diagram for the test points and
adjustment controls.
@ The ground point for the measurement equipment is the test )
point indicated as GND. (When recorded on a memory scope
* p-p voltage of 8V
' * + and-— voltage roughly same
—10—