is there a ghost in my machine?

Hi, all, I've been reviving a vintage stereo setup and can't seem to isolate the problem with the right channel speakers; the right channel fades out and dies completely but only under certain circumstances.
 Here are the details:  I've got a just-renovated Linn LP12, and a Conrad-Johnson PV1 which just came back from getting its tubes checked and pots cleaned (because I wasn't getting sound in the right speakers) . I've got a Carver Power amp and Peter Sequerra bookshelf speakers. I played a couple of albums and for about an hour or so I got sound out of both speakers, then the right channel faded and died. 

I wasn't sure if the problem was the Carver or the CJ, so I used a 3.5mm to RCA jack and played my Bose radio with just the Carver and the left and right channel kept going with no fadeout or drop for three hours...so I don't think the problem is the power amp, or the speakers. 

I tried the turntable again with the CJ and got sound from both speakers for about fifteen minutes and then the right channel faded out again. Switched cables on the Carver and both speakers worked for a few minutes and then the left speaker dropped out. 

I"m not sure if there's something going on with the CJ right channel output or the Turntable output - I just had them both reconditioned, too!! It's a real head fake because the sound doesn't drop out right away.
As I see it:
- I could try another RCA cable for the CJ to the Carver  and see if that allows the turntable to play both channels for an extended period of time OR=try adding a tuner to the CJ to see if the CJ plays both right and left channels for radio ...that would tell me the CJ is fine and the problem is in the right channel in the turntable somehow. The Linn cartridge, I was told, is fine; however I've also heard-that the cartridge head has right and left channel wiring and maybe that's the issue. 
I haven't had problems with sound in both channels bypassing the CJ and the turntable and playing a radio and an Mp3 with just the Carver.  
I'm open to suggestions.  It's interesting that I got a good two hours with the CJ and the Linn from both speakers when the turntable and the CJ hadn't been used for weeks..  Do I need to put a fan in the stereo cabinet?