Casio AP-40 Service Manual page 15

2. No sound
Does the power indicator
Check the main volume.
Disconnect CA and CB
connectors on the main PCB.
Does the demo tune sound?
Replace keyboard PCBs.
3. Distorted sound
light up?
Yes
Is it OK?
Yes
Press Demo button.
Yes
Check the voltage selector.
Is it at proper position?
Yes
Replace the main PCB.
No
Follow "No power"
troubleshooting.
No
Replace main volume.
No
Replace the main PCB.
No
Set the voltage selector at
proper position.
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