Right Channel dropped out Bryston BP-26P (upgraded from BP-25P)


Long-time member/reader, first time poster  Moved my speakers to new location (used Cardas recommended measurements per post I read today on AudioGon site.  Long story short, turned on system, no right channel.  However, balance ctrl in center, I have left channel output in both speakers. Balance Ctrl fully to right channel...nothing.  Same whether it's switched to Mono or Stereo.  Found negative spade connector off on right speaker (did not seem to be touching positive terminal.  Reconnected still have the problem  Using Bryston 4Bcubed amp.  Both channel lights are green so I don't think it's the amp.Suspect preamp is taking a trip back to Bryston. However, also saw a post that said to clean input selector contacts, which I can do? Any suggestions welcome.  BTW  It's out of warranty
deanrk
The balance control issue is driving me nuts! It doesn’t make any sense.

However, balance ctrl in center, I have left channel output in both speakers. Balance Ctrl fully to right channel...nothing.
If the Bryston 4B cubed is set to bridged mode, the 4B cubed will disconnect Channel 2 input and only take the Channel 1 input signal and send the signal to both amplifier channel. Channel 1 will amplify the signal in phase and Channel 2 will amplify the same signal but out-of-phase.
If OP connect the preamp left channel output to 4B cubed Channel 1 input and connect the preamp right channel output to 4B cubed Channel 2 input, then OP will hear both speaker playing left channel signal from the preamp, if OP listen carefully, he will notice the bass is reduced due to one of the speaker is playing out-of-phase ( opposite in polarity). That explains why when balance ctrl in center, OP had left channel output in both speakers. Balance Ctrl fully to right channel ... nothing. And that’s the reason I ask OP what is the mode setting.
However, OP had confirm the mode switch on 4B cubed was set to individual and not bridged, therefore I suspect the mode function on the 4B cubed is not working correctly.

https://img.canuckaudiomart.com/uploads/large/1913106-3942baca-bryston-4b-cubed-silver-face-with-han...

Imhififan. That makes sense to me. I boxed unit yesterday to send back to Bryston.  I’m awaiting their response. Thanks much
IMHIFIFAN. Meaculpa. After reading your last post, I unboxed the amp and………yup switch was in MONO!  And I’m sure I checked that.  Reinstalled the amp in my system, quadruple checked ALL the connections and switches, powered up the system and It worked perfectly.  Thanks for your comment and advise and link.
Human Error prevails. 
Shut everything down and went to Capital Audio Fest to unwind.