Unusual issue with my AU7900 and TU7900

[KiltedCowboy]

Had both units gone over when I purchased them. All seem to work well. Then I noticed and it might have always been there. The amp has a switch for mono-normal-reverse. When using phono or aux inputs works fine. When switching to tuner on normal setting get nothing from right channel, reverse get nothing from left channel. Mono is working on both channels when listening to the tuner. Trying to figure out if issues are with the tuner or the amp and what might be causing the problem.

 

[DB-7]

If the aux is working fine, then plug the tuner into the aux and see if it changes anything.

 

[skippy124]

If one channel is out on the tuner then you will get the symptoms as described. Using the aux input as suggested above will confirm if the tuner is working on both channels.

Edit - The AU 5900/6900/7900 all have the “horizontal” input RCA’s and it is not uncommon to have intermittent contacts where the RCA jacks for all inputs are soldered to the PCB underneath the panel that the jacks come through. If you do have one channel out that would be my first place to look (and you can do continuity checks to confirm this once the fault is isolated)

Hope this helps

Cheers
John

 

[KiltedCowboy]

Thanks to everyone. Taking the advice to swap out the tuner into the aux plug which is working properly was when I found the culprit. Sometimes we get lucky.
Little embarrassed to say it was a cable. it was not fitting snugly enough and cutting out. I swapped out the cables till I found one that was snug. Every thing working properly. No need to drag to a shop. Y'all are the best.