Amp Shutting Down, need help


I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment. I have sent the unit back to Cary where it tests fine. I have tried the unit at my friend’s apartment and his place of work and it works fine. The unit is 100% in working order. After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

The good news is that I have a dedicated 20amp circuit to this outlet. My voltage reads 118 volts and Cary said that is not a problem as the unit will work between 90 and 130 volts. I have tested for voltage on the negative lead to ground and there is no stray voltage. I have also tried the unit on other outlets in the apartment and the same problem occurs.

My mono blocks and all other components work just fine. So I’d love to hear suggestions as to how to get rid of this 50’ extension cord?

Thanks in advance.
sailcappy
I had GBART make me a DC Blocker and plugged it in and it did not solve my problem. I will say that GBART created a beautiful box for me. Really good quality. I highly reccomend him if you have DC Blocking needs. BTW mine is now for sale as I do not have DC issues with my line. Check it out under DYI.

On to the Brick Wall. More info to come.
Sailcappy, what happens if you short the input of the amp? Does it still do it?