NAD M3 Service Manual page 18

2.Preamp operation flow
Power on
Amber LED change to
blue?
YES
Wate for 10 second
Hear the relay's click?
YES
Press listen,mode,biamp key
to change input and out put
mode
Relay respond properly?
YES
Input 2V RMS 1K sinewave,turn
volume to 0dB,measure
preoutput level and THD
Level=2V±0.1V ?
YES
B
NO
Check FPP board
Check 24V relay suply
NO
Check U113,U108,U213,U208
Check HCLK,HDATA,FUNC signal
NO
NO
THD>0.01%?
YES
Check U101,U201,U106,U206
3-4
Check U105,U205,U104,U107,U204,U207
NO
Check VOL_ CLK,STB,DATA(L/R) signal
Check VOLA signal and 1Q28
Check Q103,Q203,Q101,Q102,Q201,Q202