NAD 3155 Pops when turned off


Have my sons college setup ready to go. He has a set of B&W 685s, NAD 3155, Audinst MX1 and Emotiva speaker cables.
Each time you turn the NAD off you get a pop through the speakers. Volume level does not matter. We spent time cleaning all the rca inputs, power plugs, buttons/knobs with deoxit and deoxit gold. That did take care of a cracking in the left channel when the volume knob was adjusted.

Is there a solution to the pop when powered off? Or is this normal with these older NADs?
Thanks in advance for your help.
blandis
That's normal for older NADs. Have to just live with it. Just make sure the volume control is at 0 and should not pose any problems for the speakers.