H Parabola Waveform Adjustment (Da Board) - Sony VPH-G90U Service Manual

5-4-4. H Parabola Waveform Adjustment
(DA Board)
1. Input the signal of its frequency is 64 kHz.
2. Set the data value of H SIZE COARSE to "240."
3. Set the data value of V SIZE COARSE to "maximum."
4. Connect an oscilloscope to TP402.
5. Adjust RV301 so that A section of a waveform is
identical with B section.
Specification: A level = B level
B
6. Adjust RV302 so that C section of a waveform is 0
± 0.01 V dc.
Specification: C level = 0 ± 0.01 V dc
7. Repeat steps 5 and 6 until satisfy the specifications.
5-6
A
C
0 V ±0.01 V dc
5-4-5. H SIN Adjustment (DA Board)
1. Input the signal of its frequency is 64 kHz.
2. Set the data value of H SIZE COARSE to "240."
3. Set the data value of V SIZE COARSE to "maximum."
4. Connect an oscilloscope to TP403.
5. Adjust RV402 so that A section of a waveform is
identical with B section.
Specification: A level = B level
6. Adjust RV403 so that voltage of A and B sections are 0
± 0.01 V dc.
Specification: A and B voltages = 0 ± 0.01 V dc
7. Repeat steps 5 and 6 until satisfy the specifications.
A
B
A
5-4-6. H SIN x x x x x VP Waveform Adjustment
(DB Board)
1. Input the signal of its frequency is 64 kHz.
2. Set the data value of H SIZE COARSE to "250."
3. Set the data value of V SIZE COARSE to "180."
4. Connect an oscilloscope to TP102.
5. Adjust RV202 so that A section of an envelope
waveform is 0 V.
A
B
0 V ±0.01 V dc
0 V dc
VPH-G90E/G90U/G90M