Sharp SX76NF200 Service Manual page 10

TROUBLE SHOOTING FLOWCHART
0V
Check L1302, L1303
D746 and D748
Check IC1301, IC1302 and Speaker
NO SOUND
Check sound setting by R/C.
Siganl should be received.
Check C1302(C1309) Voltage
Approx. 13V(-13V)