Casio AP-10 Service Manual page 14

2. No sound
Yes
Replace MA1M PCB.
Press "Hall" button.
Does the LED light up?
Yes
Measure voltage at pin 9 of CA
connector.
No
Is the voltage +5 V?
Yes
Set main volume to maximum.
Touch pin1 of CA connector
with test rod (+) of multimeter
in resistance range, connecting
test rod (-) to ground.
Is a noise made?
No
Touch pin2 of CF connector
with test rod (+).
Is a noise made?
No
Replace PS2M PCB.
No
Yes
— 14 —
Follow from (A) of "No sound"
troubleshooting.
Check main volume and
connection to the volume.