Pc Gain Adjustment; Pc Gamma Shift Adjustment; Htdv Pedestal Adjustment - Canon LV-7545U Service Manual

2.7 PC Gain Adjustment

1. Input 1 Receive the 16-step gray scale computer signal in COMPUTER mode.
2. Enter the service mode.
3. Connect an oscilloscope to test point "TP531" (+) and ground (–).
4. Select item no. "4" of group no. "4" and change data value to "600". Then, reduce
data value and adjust it so that waveform "a" has the minimum amplitude.
5. Connect the oscilloscope to test point "TP501" (+) and ground (–).
6. Select item no. "5" and set data value to "600". Then, reduce data value to adjust it so
that waveform "a" has the minimum amplitude.
7. Connect the oscilloscope to test point "TP561" (+) and ground (–).
8. Select item no. "3" and set data value to "600". Then, reduce data value to adjust it
so that waveform "a" has the minimum amplitude.

2.8 PC Gamma Shift Adjustment

1. Input 1 Receive the 16-step gray scale computer signal in COMPUTER mode.
2. Enter the service mode
3. select item no. "6" of group no. "4" and change data value to adjust it so that the
correct gray scale screen appears on the screen.

2.9 HTDV Pedestal Adjustment

[480p pedestal adjustment]
1. Input 3 Receive the 16-step gray scale component [480p] signal in COMPONENT
mode.
2. Enter the service mode.
3. Connect an oscilloscope to test point "TP21G" (+) and ground (–).
4. Select item no. "1" of group no. "3" and change data value to adjust the pedestal level
and black level to be same level.
5. Connect the oscilloscope to test point "TP21B" (+) and ground (–).
6. Select item no. "14" of group no. "5" and change data value to adjust the pedestal
level and black level to be same level.
7. Connect the oscilloscope to test point "TP21R" (+) and ground (–).
8. Select item no. "13" and change data value to adjust the pedestal level and black level
to be same level.
White Level
(a)
Fig. 3-6
Pedestal Lebel = Black Lebel
Fig. 3-7
3-13
Part 3: Adjustment