Casio QV-8000SX, Service Manual & Parts List

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5-4. VCO free run frequency adjustment
Room temperature should be 20
±
10
°
C
1. Preparation
• AC adaptor or voltage regulator
• Frequency counter
2. Adjustment procedure
(1) Connect SYF (CP733) and GND (CP350).
(2) Monitor HDB (CP304) with frequency counter and adjust VR320 so that frequency becomes 15.734
±
0.1 KHz.
(3) After completing adjustment, disconnect SYF (CP353) and GND (CP350).
3. Notes
When unable to adjust using AC adaptor, use voltage regulator and supply power to be VCC-1-1.
(CP105) = 5.0
±
0.05 V.
5-5. BL drive voltage adjustment
1. Preparation
• AC adaptor or voltage regulator
• Multimeter
2. Adjustment procedure
Make sure that BL-VCC (CP910) is within 5.4
±
0.2V.
3. Notes
When unable to adjust using AC adaptor, use voltage regulator and supply power to be VCC-1-1
(CP105) = 5.0
±
0.05 V.
5-6. VCOM AC adjustment and VCOM DC coarse adjustment
1. Preparation
• AC adaptor or voltage regulator
• Digital oscilloscope
2. Adjustment procedure
(1) Make sure amplitude of VCOM output (CP351) is 6.6
±
0.3 Vp-p.
(2) Adjust VR321 so that maximum VCOM output (CP351) will be 4.8
±
0.2 V.
3. Notes
When unable to adjust using AC adaptor, use voltage regulator and supply power to be VCC-1-1
(CP105) = 5.0
±
0.05 V.
4. Connection diagram
Power supply
L-PCB
QV-8000SX
VCC2
(CP972)
VCOM
(PC351)
High level
4.8
±
0.2 [V]
0 [V]
–1.8 [V]
Amplitude
6.6
±
0.3
[VP-P]
Oscilloscope