Sub-Brightness Final Adjustment; Horizontal Centering; Vertical Size; Mts Circuit Adjustments - Panasonic CT-1388YD Service Manual

Service adjustments (electronic controls, continued)

Sub-Brightness final adjustment

Service DAC (B03)
Perform this adjustment at the end. After all picture
adjustments.
Preparation:
1. Turn the receiver ON and allow 20 min. warm up at
high brightness (white screen).
2. Apply a black-white cross pattern
3. Preset the following controls for best results:
• Picture . . . . . . Max
• Bright . . . . . . . Center
Procedure:
1. In service mode, select sub bright register B02
2. Adjust register until get the 7.5 IRE section looks
the same light output than 3 Ire section,
(see Fig. 27)
3 IRE
7 IRE
Figure 28. Sub-bright adjustment
3. Exit Service Mode.

Horizontal centering

Service DAC (C09)
Preparation:
Connect a monoscope pattern.
Procedure:
1. In the service mode select the horizontal centering
adjustment DAC (C09) and adjust until the center
of the pattern is centered on CRT. Distance A
should be same than B
A=B
A
Figure 29. Horizontal centering
2. Exit service mode.

Vertical size

Service DAC (C06)
Preparation:
Procedure:
1. In the service mode select vertical size adjustment
2. Exit the service mode.

MTS circuit adjustments

(stereo models only)

The MTS Circuit adjustments require two steps:

1. Input level adjustment.

2. Stereo separation adjustment.
Input level adjustment (M00)
(stereo models only)
Preparation:
1. Connect an RMS meter with filter jig as shown,
2. Connect an RF signal generator to the RF
Procedure:
1. Apply the following signal from the RF signal
B
2. Adjust the MTS Input level adjustment (M00) until
- 29 -
Connect a monoscope pattern.
DAC (C06) and adjust until obtain a perfect round
picture.(Upper and lower section of the pattern
may go out of the visible are)
A
A B ~ ~
Figure 30. Vertical size
(see Fig. 30).
RMS
METER
4700p
Figure 31. Filter jig
antenna input.
generator:
Video: 100 IRE flat field, 30% modulation.
Audio: 300Hz, 100%
(70 ±5dB, 75Ω OPEN, P/S 10dB).
the voltage measured is 106 ± 6.0mV rms.
B
TPE11
10k
modulation, monaural