Service manual
30
VL-WD250U
VL-WD450U
3. COMMON PULSE adjustment
Test point TL1801(C OUT) Address VCR ADJ 29(C)
Mode VCR AV input
Procedure 1) Connect TL1800 to GND.
2) With VCR ADJ 29, adjust the output voltage of TL1801 and the DC voltage value of the digital voltmeter to the
specified adjustment values.
Adjustment 7.05V ± 50mV
rating
Examples • During E
2
PROM (IC703) replacement. • During D/A Converter (IC4701) replacement.
4. COM-BIAS adjustment
Test point LCD panel display surface Address VCR ADJ 33
Mode VCR AV input
Procedure 1) Input the white 100% signal to AV input.
2) Set up the illuminance meter (TOPCON IM-3) on the LCD panel surface. (The outside light must not enter.)
3)Minimize the ripple of the output waveform of the illuminance meter.
Adjustment Minimum
rating
Remark Make this adjustment after 5-minute or longer aging.
Examples • During LCD monitor replacement. LCD Panel • During IC4701, IC703 replacement.
Response time
F
0.6se
c
5. White Balance adjustment
Test point LCD panel display surface Address VCR ADJ 84(R), VCR ADJ 86(B)
Mode VCR AV input
Procedure 1) Input the white 40% signal to AV input.
2) Input the white 40% signal to the standard monitor, and adjust it to become equal to that of the screen.
Adjustment Standard monitor
rating
Remark Make this adjustment after 5-minute or longer aging.
Examples • During LCD monitor replacement. LCD Panel • During IC4401, IC4701, IC703 replacement.
VIDEO I/O ENG DAC CIRCUIT
1. 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 303/304/432/423/424/425/526 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.
Note:When it is changed to the initial value FF/FF/C3/10/29/6E/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 IC4401, IC4701, IC703 replacement.
6
720
718
L
1702
TL1902
TL1906
TL1905
TL1904
TL1907
TL1903
TL1901
R1714
R1713
Q1701
C1728
TL3329TL3315TL3370
TL3341
TL3336
TL3355
TL3320
TL3330
TL3319
TL3351
TL3354
TL3327
TL3328
TL4440
TL3353
TL3325
TL3326
TL3356
TL3323
TL3324
TL3358
TL3321
TL3322
TL4436
TL3360
TL3318
TL3363
TL3362
TL3317
TL3316
TL3368
TL334
TL331
R3499
TL
3
TL
3
T
L
R7857
L7801
C4403
R7856
C7813R7827
C7850
R7860
IC7801
R7859
TL3366
TL4438
C7808
C7810
C7811
C7822
C7821
C7807
TL4437
TL4439
R7804
R7805
R7811
C7804
R7810
R7803
TL3364
R7813
C7806
R7807
C7802
R7808
R7809
R7806
TL3365
R7802
R7814
R7812
C7805
C4417
R7801
R7800
TL3350TL3345
C4430
C7800
C4401
L7800
R4414
C4421C4419
R4401
C4410
L4402
TL1925
L4401
TL4415
C4413
R4450
R4412
C4404
TL3371
IC4471
TL7823
TL4405
Q4440
C4440
C4402
R4441
TL3343
C4441
TL4404
R4418
R4402
R1725
R4416
R4440
R4430R4427
R1726
R1727
R1728
IC4472
C4409R4419
R4417C4408
R1723
R1724
R1720
R1733
R1734
R1721
R1708
R1709
TL1701
TL1915
Q1401
TL1917
R1711
R1710
C1708
R1707
R1704
R1451
C1704
L
1702
C
1712
C
1710
C1416
717
714
4
52
1
431
R
1442
C1409
C1404
C1414
R1454
C1436
C1410
D1402
Q1434
C1408
C1413
R4487
C1405
R4429R4499
R4420
R4423
C4406
R4436
Q4482
R4426
R4421C4407
TL4403
TL8800
R4422
R4443
R4442R4437
R4488
Q4442
Q4441
Q4433
Q4434
C4405
R4425
C4436
R4413
R4410
R4408
R4406
R4407
R4405
R4404
R4415
C4411
R4435
R4411
R4409
C4435
C4412
C4472
C4482
TL4416
C4420
C4422
R4475
TL4417
C4423
C4426
IC4401
C4427
C4451
TL4434
R4451
R4452
TL4433TL4435
R4456
TL4428
TL4429
C4431
R4494
D7800
C7815
C7842C4432
C784
1
R785
1
C445
4
C78
4
L4451
C7837
C4
4
R4
4
R445
3
IC4461
Q4462
R4464
R4469
X4451
Q4461
R4460
TL28
C4466
C4463
R4463
C4464R4468
TL23
R4467
D4451
L4461
R4473
C4461
L601
Q4471
R4478
R4474
C4424
R4477
Q4431
L4481
Q4472
Q4432
C218
R4424
R4428
R4486
C4483
C215
Q4481
R4485
C4485
C4481
R1438
C1432
R1432R1431
TL207
R1439
C212
R1440
Q1432
C
1437
4
41
4
34
IC202
TL211
TL212
TL210
TL38 TL33
C641
TL29
TL27
TL26
TL36
TL34
TL32
TL31
TL30
TL37
TL35
TL7823(GND)
DAC_Y, DAC_R-Y, DAC_B-Y
TL4403(Y OUT)
DAC_Y
TL4405(B-Y OUT)
DAC_B-Y
TL4404(R-Y OUT)
DAC_R-Y
(Wiring board diagram: Main Side B)