Yamaha A-S801 no output

Just bought a used Yamaha A-S801.  Hooked it up to Yamaha CD-S2000 via RCA cables with Furutech locking connectors and Sonus Faber Lumina III speakers to the A speaker pair of connectors on the back of the '801.  The spades were too big so got some spade-to-banana adapters and went that route.  Still nothing.  Replaced the speaker cables with simple 14-gauge wire, still nothing.  I know the CD player works and the 801 powers up as expected.  Tried switching various combinations of the A-B-A+B speaker switch.  Nothing.  Tried using both high and low impedance slider.  Nothing.  Spoke with the seller and he said it worked fine when he sent it to me.  His feedback is uniformly excellent so I have no reason to disbelieve him.  No signs of damage to the box or the unit itself (which is immaculate).  The owners manual is silent on the subject, simply advising me to turn up the volume (why didn't I think of that).

Any suggestions?  

Thanks very much!