NAD M4 Service Manual page 14

2. Operation flow
Power on
Orange LED change to
blue?
YES
Wait for 10 second
Hear the relay's click?
YES
Press band key to change
source FM,AM,DAB/XM
mode
Relay respond properly?
YES
Press band key to select AM
mode, input AM test signal
1K 500mV sinewave at antenna
side,check output
Level=0.5V±0.1V ?
YES
A
NO
Check FPP board
Check 5.3V relay supply
NO
Check Q101
Check SOURCE SELECT signal
NO
NO
THD>3%?
YES
Check C425 board
3-3
Check conection between C425 and main
NO
board
Check RL101 RL102 R184 R185