Panasonic BT-H1700P

48
CONTRAST ADJUSTMENT (NTSC/PAL Y/C)
Measuring Instruments Signal generator (Crosshatch signal)
Oscilloscope
Card (Slot) NTSC/PAL Video Input Card (Slot 2)
Test Points TP-47G [CRT SOCKET PWB]
TP-GND [CRT SOCKET PWB]
Adjustment Points S*01 (4:3 Overscan Contrast), SM** (4:3 Underscan Contrast),
SN** (16:9 Overscan/Underscan Contrast) [Service Menu]
Notes: • Ensure that the output waveforms from the NTSC/PAL
Video Input Cards are normal before proceeding to the
following adjustments (see page 72).
• Perform the following adjustments after completing the
1080/60i signal Contrast Adjustment.
• Set the CONTRAST data in the Setup Menu to "00".
• The SO value (see the description of the HDTV Contrast
Adjustment) becomes the reference value for the follow-
ing adjustments. When this data is changed, it is required
to re-adjust the data of all of the adjustment signals (HDTV,
SDTV and NTSC/PAL).
When re-adjusting the 1080/60i signal, use the SI. (For
the adjustment of the 1080/60i signal, use the Compo-
nent/RGB Input Card.)
• When overscan data of a signal is changed, it is required
to re-adjust the underscan data of the same adjustment
signal.
• When the 4:3 data of a signal is changed, it is required to
re-adjust the 16:9 data of the same adjustment signal.
1. Apply the NTSC crosshatch signal to INPUT D (Terminal Y/C on the
NTSC/PAL Video Input Card).
2. Set the CONTRAST potentiometer on the front panel to the center
click position.
3. Connect the oscilloscope across TP-47G and TP-GND.
4. Adjust SB01 in the Service Menu to set the voltage amplitude <A>
in the figure on the right to 30 V ± 2 V.
5. Set the ASPECT button on the front panel to ON so that the scan-
ning size is 16:9.
6. Adjust SN07 to set the voltage amplitude <A> to 30 V ± 2 V.
7. Set the ASPECT button on the front panel to OFF and the UNDER
SCAN button to ON to set the scanning size to underscanning for
the 4:3 ratio.
8. Adjust SM04 to set the voltage amplitude <A> to 30 V ± 2 V.
9. Set the ASPECT button on the front panel to ON to set the scanning
size to underscanning for the 16:9 ratio.
10. Adjust SN10 to set the voltage amplitude <A> to 30 V ± 2 V.
11. Set the ASPECT and UNDER SCAN buttons on the front panel to
OFF.
12. Vary the adjustment signal and adjustment data, and re-perform
adjustments in steps 1 to 11 above (see Table 4).
1 Vertical interval
(V. sync)
<A>
30V ± 2V
Table 4
Adjustment
Scanning Size
Aspect Ratio
Signal
4 : 3 16 : 9
NTSC
Overscan SB01 SN07
(Y/C)
Underscan SM04 SN10
PAL
Overscan SD01 SN19
(Y/C)
Underscan SM10 SN22