The right channel comes and goes (fades in for 10 mins then goes for one minute then fades back again) I've swapped the card and the problem does not follow the card. The source is definately there, but I can't pursuade it to hang around for too long...

Anyone experienced this previously?

Couple of things you could try, Instead of using N/S 1 try N/S 2 input, another thing you could try is the way you decode, you could try pro logic or Lt Rt Direct and see if this helps, to do this consult your installation manual. Lastly I would double check the CD player, running direct output to separate speakers just in case it could be the player

Hope this helps you out

I've already tried the different formats. Non-sync 2 is used for the Talkie Tape so that's not an option unfortunately.

The fault is definately within the 500 as swapping the inputs to the 500 from the cd doesn't change a thing on the 500 it's always the right channel.

Something I've noticed this week though...it can be absent all morning during maintainance time but once a session has been run...it's back. This happens every morning.

Assuming that your optical formats are okay, your NS2 format is okay and reversing your inputs maintains problem on right channel, I would think your problem may be on the Cat. No. 681 card. Try swapping it out if you can...