31
VL-Z400S-T/H-T
VL-Z500S-S/H-S/E-T/E-S
ADJUSTMENT OF VF CIRCUIT
(Wiring board diagram: Main Side A)
2. Adjustment of VF_COM amplitude (Main PWB)
Measurement point
TL8801(VF_COM)
Address
VCR ADJ 32
Procedure
1) Set the data value at address 5EB (TESTSW2) to 77.
2) Connect the digital voltmeter to TL8801 (VF_COM). At address 32 (VF_DAC_C), adjust the DC
voltage to the adjustment rating.
Adjustment rating
3.5V
±
50mV
Examples
· Replacement of IC705
1. Setting data
Address
4AF
4B2
4C1
4C4
582
58C
Data
77
30
68
B0
48
90
3. Check of electromagnetic conversion circuit system (Auto check of playback envelope signal quality and error rate)
Mode
VCR adjustment mode
Procedure
1) Insert a recordable tape and enter the VCR mode.
2) Press the "CONTINUE"
→
"TEST SEL" keys on the remote control for adjustment to enter the TEST mode.
("T-01" is displayed on the LCD.)
3) Select "T-0F" using the FF or REW key and press the PB key.
4) LP recording of the color bar/rewind/playback and playback envelope/error rate are inspected automatically.
5) The results are displayed about 50 seconds after the start.
(1) ENV NG: Playback envelope signal amplitude or balance between channels is lower than standard.
(2) SYNC NG: SYNC error rate is lower than standard.
(3) ECC NG: ECC error rate is lower than standard.
(4) CK-OK: No problem.
* If one of the error inspections 1 to 3 is NG, the result is displayed and the test ends at that point.
(Inspections following that are not executed.)
6) Turn off the main unit to exit.
Examples
• When replacing the mechanism.
• When confirming a defect of the electromagnetic conversion system such as dirty video heads.
TL1207
SC1800
P3301
TL1812
2
TL1810
TL1809
TL1808
TL1206
R
C1813
C1815
C1439
R707
R747
R732
L1803
R1814
L1802
R715
C736
C735
L1404
C1402
C1812
R1816
C1441
R1813
Q705
C708
Q704
R1406
C704
C1408
R772
R771
R718
R738
R736
R1817
C1416
C1814
C1410
C1407
C1406
C1808
C1809
C1810
C1811
R737
R729
R1807
R1405
IC1401
R763
R759
C1409
C1418
R1824
R1825
R1826
R1823
R1822
C710
R1413
R1401
C1417
R1461
Q1405
C1411
R1821
R735
R1421
C1419
R1828
R1403
R1462
R1414
Q1403
IC1800
R1404
R1424
TL1450
R1820
R725
C733
C4424
R6839
R1423
R1422
R6836
R6835
TL1452
C1412
R6840
R720
R755
R246
C220
C6827
R1827
Q6800
Q1802
Q1404
R6833
C4422
C6801
Q1402
R219
C219
TL206
R6832
R1803
R1804
C1802
C1803
C1804
R1800
C1801
R1801
C6829
C6828
TL207
R1402
R1419
C4401
C4417
R4415
C4418
TL1451
TL6807
TL205
C4425
R4473
R6837
R6807
R6808
R706
R710
R708
R730
R782
TL8803
C717
R740
R4401
R4402
R6805
C4402
C4421
C727
C705
C715
L6800
C6800
R6800
R726
C6804
D6800
R727
R4493
C4419
C4420
TL7804
TL7805
X701
IC703
R7827
R7802
C714
R6820
R6801
C7802
R6819
R6802
R701
R7826
TL7824
IC4401
R6818
R6803
R7803
C7804
C6805
C701
C7803
C8805
L8801
R7804
R6804
R1925
C7801
C1911
R4472
R7828
C8800
R1928
Q1913
L8800
TL920
R4471
R6809
R7801
R8802
R8801
TL4470
TL7802
R1927
R6810
TL903
C1940
R1926
TL7801
TL204
C1960
Q1912
C8804
TL904
R4470
R1924
R8800
R19
4
C210
IC8800
Q8800
R1944
D960
C978
Q1907
R1947
TL203
C7810
R1900
C205
C207
C208
C211
R201
C4442
C8801
L7810
R1946
R1945
TL4440
TL916
R7811
R8804
C929
C962
R7820
R7832
R8805
TL8801
D916
R7835
Q1900
R7821
R7833
FB4402
R4403
R8866
R7838
C7812
C7829
C7828
C8807
C8809
C8806
D7810
Q8801
R
7839
R7834
R7837
C7827
C8808
R8807
R7836
C7821
C4403
Q905
TL3707
C8813
R8868
R8867
C8810
R8803
Q7800
02
L931
R8809
R8806
C8802
R8827
R8814
TL907
C3704
3
707
R3727
TL8802
Q8802
C8803
R8828
R3705
C3710
TL911
R8808
R8817
L907
R3717
IC3702
Q909
C953
FB3701
C939
L908
R982
C3705
C3708
C938
C3712
C1901
Q903
TL921
C3709
Q1901
C3729
C3727
C3728
C3725
L901
TL908
Q900
C3702
L3702
TL8806
C934
C8825
TL8809
C932
R970
TL8804
TL910
C8824
C8823
7
01
L3701
TL8805
L903
C933
L902
C936
TL8801(VF_COM)
VF_COM
TL8804(VF_VG)
VF_WB
TL8805(VF_VR)
VF_WB
TL8806(VF_VB)
VF_WB
TL7824(VF_G_OUT)
VF_DAC full scale
