Panasonic WV-CM1020 Service Manual page 7

(2). Screen Cut off Coarse Adjustment
Test Point: TP802 (G)
Adjust: CUTOFF G
SCREEN Control
Flyback Transformer on the Main Board
8
Turn the Power Switch on while pressing the Increment
Button (+), the Decrement Button (–) and the MENU
Button simultaneously, and enter to the Service Menu
mode.
8
Supply the Grayscale signal to Video Input Connector.
8
Connect the Oscilloscope to TP802.
8
Set the Input Selector of the Oscilloscope to the DC Mode.
8
Select the MENU Button to the W/B MENU.
8
Select the Cursor Buttons (i) or (o) to the CUTOFF G
position.
8
Adjust the Increment Button (+) or Decrement Button (–)
so that G Pedestal becomes 110 ± 2 V as shown in Fig. 4-1.
Fig. 4-1
8
Adjust the SCREEN control so that the 8th step of stair
step becomes cut off.
(3). Contrast Adjustment
Test Point: TP802 (G)
Adjust: MAX CONTRAST
8
Connect the Oscilloscope to TP802.
8
Set the Input Selector of the Oscilloscope to the AC Mode.
8
Select the MENU Button to the SUB MENU.
8
Select the Cursor Buttons (i) or (o) to the MAX
CONTRAST position.
8
Adjust the Increment Button (+) or Decrement Button (–)
so that the output of TP802 becomes 40 Vp-p as shown in
Fig. 4-2.
CRT Board
Increment Button (+)
Decrement Button (–)
110 ± 0.2 V
GND
CRT Board
Increment Button (+)
Decrement Button (–)
– 4 –
Fig. 4-2
(4). Colour Adjustment
Test Point: TP803 (B)
Adjust: STD COLOUR
8
Supply the Colour Bar signal to the Video Input Connector.
8
Connect the Oscilloscope to TP803.
8
Select the Cursor Buttons (i) or (o) to the STD
COLOUR position.
8
Adjust the Increment Button (+) or Decrement Button (–)
so that the output of TP803 becomes 15 Vp-p as shown in
Fig. 4-3.
Fig. 4-3
(5). H & V Centering and Size Coarse Adjustment
Adjust: VR401 (V-SIZE)
VR403( V-CENTER)
L502 (H-SIZE)
H-CENTER
Observe: Colour Video Monitor
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Select the MENU Button to the DEF MENU.
8
Select the Cursor Buttons (i) or (o) to the H–CENTER
position.
8
Adjust VR403 so that the Monoscope Pattern signal
positions at the vertical center on the CRT screen.
8
Adjust VR401 so that the full vertical height becomes plus
6 % overscanning.
8
Ajust L502 so that the full horizontal width becomes plus 8
% overscanning.
40 Vp-p
CRT Board
Increment Button (+)
Decrement Button (–)
15 Vp-p
Main Board
Main Board
Main Board
Increment Button (+)
Decrement Button (–)