Hello Everyone, I'm Jim and a relative Newbe. I recently bought some Pass and Threshold Electronics Love the sound.

Are those units new or used.? If used, maybe there is dirt or corrosion. Or the interconnect cables could be bad.
Have you determined that the problem is in one specific component yet? That is easy to do.
 
Thanks Rayma, Yes they're used. I had a local techy go through the amp and he replaced some caps. I bought the preamp a month ago and it seems fine as it was plugged into an NAD amp. All was well. My techy replaced a fuse yesterday and shortly after I turned the system on, I lost the R speaker. Any insight on that sort of thing.
Jim.
 
This makes it more likely the problem is in the amplifier. Is there any sort of warranty on the amp?
Where was the fuse, inside or outside the amp? Perhaps the fuse was too small, or there is a problem.
Can the tech come to your home to do the work?