Onwa KR-1338 Service Manual page 50

Flow chart 7
NG
GAIN VR at maximum.
OK
Confirm GAIN control
voltage with VR fully CW.
NG
Is J101 #15 on MAIN
0910 about 0V.
OK
Check if video signal is
input to display unit.
Level of U41#3 on
MAIN-09101 normal.
OK
Faulty pcb MAIN-0910.
46
Symptom: No echoes nor white noise.
Set GAIN VR at maximum.
Faulty VR1 on KEY-0912 board.
0V
Approx. -4V
Check for shorted or disc-
onnected video signal line
between anntena unit and
display unit.
Yes
Disconnected or
shorted.
No
NG
12 V line on
antenna unit
OK
Faulty pcb IF AMP.
KR-1338/1668: IF-0711
White noise.
Faulty cable on video line.
Faulty cable on video line.