hifi engine

Troubles with Harman Kardon AVR130

hi guys,
i've inherited an AVR130 from my dad..The problem is the following
i've currently got FL,FR and Center attached..unfortunatly, for some unknown reason, Front Right only works in "surround off" mode..in none of the other settings i can get it to work..
my sister managed to lose the remote so i can only use the front on the actual receiver. I'm currently looking for a remote to replace the old one so if i really need that to sort this thing out let me know.

so the problem is: Front right speaker works but ONLY in surround off...no idea what could be the problem