Service manual
32
VL-AX1U
5. White Balance adjustment
Test point LCD panel daisplay area Address VCR ADJ 84(R), VCR ADJ 86(B)
Mode VCR AV input
Procedure 1) Input white 40% signal into the AV input.
2) Input white 40% signal into the standard monitor, and adjust it until it becomes the same as that screen.
Adjustment Standard monitor
rating
Remark Make this adjustment after 5-minute or longer aging.
Examples • During LCD panel replacement. • During IC705, IC4401, IC4701 replacement.
4. COM-Bias adjustment
Test point LCD panel display area Address VCR ADJ 33
Mode VCR AV input
Procedure 1) Input white 40% signal into the AV input.
2) Set the illuminometer (TOPCON IM-3) on the LCD panel surface. (Shut off the external light.)
3) Minimize the ripple of output waveform of illuminometer.
Adjustment Minimum
rating
Remark Make this adjustment after 5-minute or longer aging.
Examples • During LCD panel replacement. • During IC705, IC4401, IC4701 replacement.
Response time : 0.6 sec.
VIDEO I/O ENG DAC CIRCUIT
(Wiring board diagram: Main Side B)
6. DAC_Y adjustment, DAC_R-Y adjustment, DAC_B-Y adjustment
Test point TL4403(Y OUT), TL4404(R-Y OUT), TL4405(B-Y OUT), TL7823(GND)
Mode CAM
Address VCR ADJ FA(Y), VCR ADJ FB(R-Y), VCR ADJ FC(B-Y)
Procedure 1) Set VCR ADJ 303/304/432/423/424/425/426 to 0C/EF/63/90/EB/80/80.
2) With VCR ADJ FA, adjust the output voltage of TL4403 and the DC voltage value of the digital voltmeter to the
specified adjustment values.
3) Similarly with VCR ADJ FB/FC, adjust the output voltage of TL4404/TL4405 and the DC voltage value of the
digital voltmeter to the specified adjustment values. (Same as Item (2))
4) Return VCR ADJ 303/304/432/423/424/425/426 to the initial value. (Initial value: FF/FF/43/10/29/6E/F0)
Note:When it is changed to the initial value FF/FF/43/10/29/6E/F0, OSD display goes out together with LCD/VF.
Checking the monitor output, adjust it. After adjustment, be sure to return to FF.
Adjustment 0.450V ± 5mV (Y OUT), 0.229V ± 2mV (R-Y OUT), 0.290V ± 2mV (B-Y OUT)
rating
Examples • During IC705, IC4401, IC4701 replacement.
TL1431
TL239TL245TL244TL243TL242TL241TL235TL240
TL1420
R257
R244
TL233
TL234
TL4438
R255
TL201
TL202
TL4439
TL4437
R243
R242
R258
C205
TL236
R206
SC201
TL237
R204
TL238
R203
R207
R208
R201
R213
R202
C204
C2509
L2501
R235
R797
R796
SC701
R2506
C2507
R2504
C2508
R2502
R2501
C2506
C2505
TL2802
C2504
TL2801
C2502
C2503
SC2501
TL2800
C2553
Q2503
C2554
C2511
R2518
L2502
R2524
R2537
R2523
R2517
Q2508
Q2501
L
5789
R2534
C2513
R2513
TL5790
Q2507
R2510
TL5788
TL5786
R2533
Q2504
Q2502
R521
R522
TL5778
TL5752
R523
R2532
C2555
C2556
R2538
C2530
C2531
TL4405
TL7801
TL4403
R2503
IC2501
TL4404
R2505
C2501 C2510
C202
C501
L501
TL912
C5701
C5703
C5704
C5702
FB203
C208
C210
C239
C222
R205
C224
R209
C231
C223
TL7823
C226
IC201
C227 C228 C240 C235
TL4441
TL908
C209
C211
C212
C215
FB204
R251
L204
C203
C213
IC202
C230
FB201
R526
C507
R509
TL7800
TL4440
IC501
70
C5
R5
3
C5
0
C5
R5
3
C5
0
R5
0
R5
0
C5
0
R5
3
R5
3
TL5780
R506
80
R
C237
C
1
R1934 R1935
C238
Q1
9
TL4405(B-Y OUT)
DAC_B-Y
TL7823(GND)
DAC_Y,
DAC_R-Y,
DAC_B-Y
TL4404(R-Y OUT)
DAC_R-Y
TL4403(Y OUT)
DAC_Y