Onwa KR-1338 Service Manual page 48

Flow chart 5
NG
Warm up countdown.
OK
NG
Only one key is faulty.
OK
Single vertical row only.
Single vertical row
of keys is faulty.
All keys
Cable between pcb PNL and pcb SPU damaged.
Faulty pcb MAIN-0910
44
Symptom: key(S) inoperative.
Faulty pcb MAIN-0910.
Faulty VR1 or VR2 on pcb KEY-0912, S1 to S12
on pcb KEY-0912
Faulty lines #10 and #11(KEY 2) of the W301 on
KEY-0912. Cable between pcb PNL and pcb SPU
damaged. Faulty pcbMAIN-0910.