- 23 -
Service Adjustments (Electronic Controls, cont.)
21. EXIT the Serviceman Mode.
22. Adjust the Picture Menu Video Adjustments Bright
and Picture from low scale to high scale and check
Black and White tracking.
23. If correction is needed: Re-Enter the Serviceman
Mode and perform the Minor Touch – Up Method.
24. Perform Sub-Brightness Adjustment procedure if
needed.
Horizontal Centering
Serviceman DAC Adjustment (C9)
Preparation:
Connect a crosshatch generator.
Procedure:
1.
In the Serviceman Mode for making electronic
adjustments. Select the Horizontal Centering
Adjustment DAC (C9) and adjust until the center of
the crosshatch pattern is centered on CRT.
2.
EXIT the Serviceman Adjustment Mode.
Audio Adjustment
Serviceman DAC Adjustment (B6)
This adjustment is factory set and needs to be
performed only when IC002 or IC101 is replaced.
Preparation:
1.
Apply the following signal at the antenna
(70dB ±5dB, 75
Ω
open P/S 10dB): audio signal set
to monaural, 300Hz. 100% modulation; video input
of 100 IRE flat field, 30% modulation.
2.
Connect the RMS Meter with filter jig as shown in
Fig. 23.
Procedure:
1.
In the Serviceman Mode for making electronic
adjustments, select the Audio Adjustment DAC
(B6) and adjust until 350mV ± 12.5mV RMS is
measured.
2.
EXIT the Serviceman Adjustment Mode.
Input Level Adjustment (M0)
Preparation:
1.
Connect an RMS meter with filter jig as shown in
Fig. 24.
2.
Connect an RF signal generator to the RF
antenna input.
Procedure:
1.
Apply the following signal from the RF signal
generator:
Video: 100 IRE flat field, 30% modulation.
Audio: 300Hz, 100% modulation, monaural
(70 ±5dB, 75
Ω
OPEN, P/S 10dB).
2.
Adjust the MTS Input Level Adjustment (M0) until
the voltage measured is 212 ± 10.5mVrms.
10k
4700p
Figure 23. Filter Jig
TPE1
RMS
(A-BOARD)
METER
10k
4700p
Figure 24. Filter Jig
TPE10
RMS
METER
