L,Bl Pcbs Assy; Vcc2 Adjustment And Vcc13, Vcc7, Vee2 Checks; Vcc Free Run Frequency Adjustment - Casio QV-5500SX Service Manual & Parts List

3. L, BL PCBs Assy

3-1. VCC2 adjustment and VCC13, VCC7, VEE2 checks

Adjustment and checking
Adjust VR151 so that VCC2 (CP172) is 5.0 ± 0.02V.
Turn the power off and make sure that all the voltages are 0V.
Notes :
<Voltages> VCC7 = 7.0 ~ 8.0V
VCC13 = 11.8 ~ 13.7V
VEE2 = -13.2 ~ -15.4V

3-2. VCC free run frequency adjustment

Condition
1. Connect CP763 (SYF) and CP700 (GND).
Adjustment
Monitoring CP734 (HDB) with frequency counter, adjust VR755 so that the frequency is 15.734 ±
0.1kHz.
Note :
Perform the adjustment in room temperature of 20 ± 10˚C.
Power
Supply
AGND
L-PCB
SYF
(CP763)
(CP700)
— 13 —
HDB
(CP734)
Frequency
counter