Electrical Troubleshooting Guide - NAD M15 C/AH Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

Power check flow
Power switch on
Amber LED
Yes
Press the standby button
Blue LED ON?
12vt power
supply is correct?
-15Va,15Va power
supply is correct?
No
ON?
No
Check Q312 , U302,U301 on
FPP board
No
Yes
Yes
No
Yes
A
No
5vs is Right?
Yes
Check Q303 , U302,U301 on
FPP board
Check U304
Check D608,F608
Check U304
Check D608,F608
Q614 Base pole
is oV?
Yes
Check Q614 collector is 0v?
Check U606
Check D603
Check F603,F604
Check Q615,Q611,Q610
Check U607
3-2
Check CON602
Check U611
Check D605
Check F609
Check Q311,U301,U302
No