Casio PX-780 Service Manual page 17

4-6. KEY/BUTTON NG
Check the connection
of CN15 and CN16.
NG
Connector is loosely
connected.
4-7. TOUCH PANEL NG
Check the connection
of CN3.
NG
Connector is loosely
connected.
4-8. LCD NG
Check the connection
of CN5.
NG
Connector is loosely
connected.
OK
FFC/FPC
damaged?
No
OK
After replacing the TOUCH
PANEL, check again.
No
OK
After replacing the LCD,
check again.
No
Yes
Check if keys are
correctly assembled.
OK
OK
TOUCH PANEL
is defective.
MAIN PCB is defective.
OK
LCD is defective.
MAIN PCB is defective.
– 15 –
FFC/FPC is defective.
No
Keys are not
correctly assembled.
MAIN PCB is defective.