Audio Research VT100 MKll Stays on

Was hoping somebody here might be able to help me I have a Audio Research VT100 MKll that stays on and wont turn off I have it plugged into one of the switched outlets on my power conditioner and I'm just turning it on and off that way but I've replaced the switch twice which both times worked for a while and then the same thing I removed the switch completely and plugged it in and sure enough it came on even without the switch I don't see anything obviously wrong with it so was hoping somebody with some technical experience might be able to tell me what to check
Thank You