Panasonic TC-25FJ20R, Service Manual

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Preparation
1. Receive a colour bar signal with colour “OFF”, and operate
the TV set for more than 30 minutes.
2. Set the picture menu to “DYNAMIC NORMAL” and the AI to
off.
3. Connect an oscilloscope to TPL5 with DC mode.
4. Set the TV set to Market Mode : white balance adjustment
(CHK 4).
5. Screen VR : Min.
6. Set the data level of RGB CUT OFF / DRIVE and SUB
BRIGHT.
Display Data Level
R-CUT OFF 63
G-CUT OFF 128
B-CUT OFF 63
R-DRIVE 128
B-DRIVE 128
SUB BRIGHT 63
Adjustment
1. Select G-CUTOFF adjustment mode and collapse vertical
scan.
2. Adjust G-CUTOFF control to become the DC=0 V to video
level at 180 V as shown in Fig. 1.
Fig. 1
3. Slowly turn the screen control clockwise until a green colour
horizontal line appears on the picture tube. This is the
setting point for the screen control.
Note:
Do not adjust the G-CUTOFF setting in the following
procedure.
4. Adjust the remaining R and B-CUTOFF controls so as to
get a white horizontal line on the screen.
5. Return to full field SCAN by pushing the position 5 key on
the remote control.
6. Adjust the R-Drive and B-Drive controls as to obtain a
uniform white on the white bar of the greyscale pattern.
7. Confirm correct B/W rendition and greyscale tracking or
repeat CUTOFF and drive control setup.
Note:
Write down the original value for each address adjustment
before adjusting anything.
8. Wedge A shown in Fig. 2 should be fixed within a range of
45° to the left of the vertical line as shown.
9. After inserting wedge A, insert wedges B, C and D.
The wedges should be set 90° apart from each other.
10. Be certain that the four wedges are firmly fixed and the
Deflection Yoke is tightly clamped in place otherwise the
Deflection Yoke may shift its position and cause a loss of
convergence and purity.
4.4. WHITE BALANCE (MARKET MODE CHK 4)
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TC-25FJ20R