Toshiba 50A50, Service Manual

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GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
ITEM ADJUSTMENT PROCEDURE
Vertical retrace line
SUB-BRIGHTNESS
(BRTC) 1. Constrict the picture height until the
vertical retrace line appears adjusting
the HEIGHT control on the MAIN board.
2. Adjust the CONTRAST to the minimum
and BRIGHTNESS to the center.
3. Enter the service mode, then select
“BRTC” register.
4. Adjust the data value so the belt of
vertical retrace line just disappear.
5. Adjust the HEIGHT control.
* Adjust the SUB-BRIGHTENESS after
adjusting the WHITE BALANCE.
SUB-COLOR
(SCOL)
SUB-TINT
(TNTC) 1. Receive color-bar signal from color-bar generator.
2. Adjust the BRIGHTNESS and CONTRAST to the center (RESET status).
3. Connect oscilloscope to TP501on the MAIN board.
4. Enter the service mode, then select “SCOL”.
5. Temporarily adjust the data value to
achieve about 1V
0-p
of blue bar.
6. Select “TNTC” register.
7. Adjust the data value to obtain the blue
bar to magenta bar ratio of 3:2 as
shown.
8. Select “SCOL” register.
9. Adjust the data value to achieve 1.8V
0-p
of blue bar on scope.
10. Check the picture with off-air signal.
0
Blue
Magenta
2
3 (1.8V
0-P
)
SUB-CONTRAST
(SCNT) 1. Tune in a color program and adjust the BRIGHTNESS and CONTRAST to
normal mode(RESET).
2. Enter the service mode, then select "SCNT" register.
3. Change "SCNT" data to13H.
4. Check the picture contrast.
ELECTRICAL ADJUSTMENT
PICTURE POSITION 1. Receive the pattern signal which shows it's center
on the screen.
2. Adjust the picture position alternately by turning
CENTERING MAGNETS for proper picture position.
3. Check the picture with off-air signal.
VERTICAL POSITION (VCEN) 1. Call up the adjustment mode display, then select item VCEN.
2. Press the VOLUME
s
or
t
button to get the v30
±
10 mV.
3. Measuring method of voltage as follows.
TP-V
TP-G C
(on SIGNAL board)
(on SIGNAL board)
DIGITAL
VOLT METER