– 6 –
5. Adjustment Procedure
8
Refer to the Location of the Test Points and Adjusting
Controls on page 9.
(1). Sub Contrast Adjustment
Test Point :
Pin 3 of A11 (G)
Main Board
Adjust :
LEVEL CONTROL (+)
Main Board
LEVEL CONTROL (–)
Main Board
8
Turn OFF the Power Switch.
8
Supply the Colour Bar signal to the Video Input
Connector.
8
Short between Anode of D504 and ground by jumper wire
to stop the ABL.
8
Turn ON the Power Switch.
8
Set the Service Mode and select the "CHK 1" mode.
8
Select the BRIGHT Item.
8
Set the BRIGHT Item to the minimum position (0).
8
Select the CONTRAST Item.
8
Set the CONTRAST Item to the maximum position (63).
8
Connect the Oscilloscope to the pin 3 of Connector A11
on the Main Board.
8
Adjust SUB BRIGHT so that the signal between Black and
White at the pin 3 of A11 does not saturate.
8
Adjust SUB CONTRAST so that the signal between Black
and White at the pin 3 of A11 becomes 3.1 ± 0.1 V.
8
Remove jumper wire from Anode of D504 and ground.
(2). Colour Output Adjustment
Test Point :
Q353-C (B) for WV-CK1420
CRT Socket Board
Q354-C (B) for WV-CK2020
CRT Socket Board
Adjust :
LEVEL CONTROL (+)
Main Board
LEVEL CONTROL (–)
Main Board
8
Supply the Colour Bar signal to the Video Input
Connector.
8
Set the Service Mode and select the "CHK 1" mode.
8
Select the BRIGHT Item.
8
Set the BRIGHT Item to the minimum position (0).
8
Select the CONTRAST Item.
8
Set the CONTRAST Item to the center position (32).
8
Select the PICTURE Item.
8
Set the PICTURE Item to the minimum position (0).
8
Select the COLOUR Item.
8
Set the COLOUR Item to the enter position (32).
8
Connect the Oscilloscope to the Collector of Q353 for WV-
CK1420 or Collector of Q354 for WV-CK2020 on the CRT
Socket Board.
8
Adjust SUB COLOUR so that the Colour Output signal
becomes 29 ± 1 Vp-p for WV-CK1420/B, 36 ± 1 Vp-p for
WV-CK1420/G, 32 ± 1 Vp-p for WV-CK2020/B and 38 ± 1
Vp-p for WV-CK2020/G as shown in Fig. 5-1.
Fig. 5-1
(3). Purity Adjustment
Adjust :
Purity Magnet
Deflection Coil
Observe :
Colour Monitor
8
This adjustment should be done after aging for more than
30 minutes.
8
Degauss the CRT using a Degaussing Coil.
8
Supply the Cross-Hatch signal to the video Input
Connector.
8
Loosen both Deflection Coil Fixing Screw and Magnet
Holding Screw.
8
Adjust the Convergence roughly by the Convergence
Magnet and Deflection Coil.
8
Move Deflection Coil to the rear direction (CRT Socket
Board side).
8
Supply the Red Colour signal to the video Input
Connector.
8
Adjust the Purity Magnet so that the Red area comes to
the center on the CRT Screen as shown in Fig. 5-2.
8
Rotate the deflection coil to find the point where the red
colour whose center portion becomes equal on the CRT
Screen as shown in Fig 5-2.
Fig. 5-2
8
Move the deflection coil forward until red colour fully
occupies the entire screen and tighten the deflection coil
fixing screw.
χ
Vp-p
NO GOOD
GOOD
RED
RED
