amp wont turn on?

I have a bryston 4BSST. It worked for about a week, started up fine, shut off fine.I recently went to power up, the soft start up procedure went as far as the clipping indicators glowing red momentarily,then the amp shuts off completely...this while the breaker on the rear panel remains in the 'on'position..the fuse panel is good,and I do not have breakers, I am in an apartment...
I notice my 3BST has a fuse but the SST does not....what might be causing this? I am tuneless.....
If you disconnect a) interconnects and b)speaker cables an try to power up does it goes on OK?
If no external connections exist and the amp powers OK then you might have a short circuit most probably in the speaker cables. If it does not then you indeed have a problem with the amp
thanks guys, I will give Bryston a call. I believe I have isolated it to the amp..... :(
Update! For fun I plugged the amp into an outlet in another room...and presto, it stays on..
The mystery however is when I use the factory power cable and the orig outlet works again?!
I can only assume my upgraded pwr cbl has an issue of some kind.