Adjustment Procedure - Panasonic WV-BM990 Service Manual

ADJUSTMENT PROCEDURE

1. Test Equipments Required
8
The following Test Equipments are required for
adjustment of the Video Monitor WV-BM990.
8
Video Signal Generator (Crosshatch Signal)
8
Monoscope Pattern Signal Generator
8
Oscilloscope
8
Digital Voltmeter
8
Degaussing Coil
8
Ceramic Screwdriver
8
Electric Torque Driver
2. Disassembling Procedure for the
Adjustment
8
Referring to Fig. 2-1, remove eight screws that secure the
Upper Cover and the Rear Cover. Remove the Upper
Cover and the Rear Cover.
Remove eight screws.
Upper Cover
Fig. 2-1
3. Connection and Setting up for
Adjustment
3.1. Connection
8
Fig. 3-1 shows the connecting diagram for adjustment
procedure of the WV-BM990.
Video Signal Generator
Fig 3-1
Rear Cover
WV-BM990
VIDEO IN
8
Connect the coaxial cable between Video Input Connector
of the WV-BM990 and Video Output Connector of Video
Signal Generator.
3.2. Setting Up
8
Set the every adjusting VRs to their mechanical center
positions.
8
This adjustment should be done after 20 minutes warm up
of the WV-BM990.
4. Adjustment Procedure
8
Refer to the Location of the Test Points and
Adjusting Controls on the page 4.
(1). Freerun Adjustment
Test Point: Pin H+ of CN501 (H+)
Adjust: VR501 (H-HOLD)
VR515 (H.PRESET)
8
Disconnect all the input signals from the WV-BM990.
8
Connect the Frequency Counter to Pin H+ of CN501.
8
Fix VR501 (H-HOLD) at its center position.
8
Adjust VR515 so that the frequency becomes 15.400 kHz
± 50 Hz.
(2). Cut Off Voltage Adjustment
Adjust: VR401 (V-HOLD)
Deflection Coil (DY)
VR301 (CONTRAST)
VR302 (BRIGHT)
VR602 (SUB-BRIGHT)
Observe: Video Monitor Screen
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Adjust VR401 to hold picture vertically.
8
Adjust the Deflection Coil so that the edges of the
Monoscope Pattern are visible in the monitor screen.
8
Turn VR301 fully counterclockwise.
8
Turn VR302 to its mechanical center position.
8
Adjust VR602 so that the Raster just appear.
(3). Picture Tilt Adjustment
Adjust: Deflection Coil (DY)
Observe: Video Monitor Screen
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Loosen the Deflection Coil Holding Screw as shown in Fig.
4-1.
– 2 –
Main Board
Main Board
Main Board
Main Board
Main Board
Main Board
CRT Board