Help with Kora Explorer

I purchased a Kora Explorer integrated a while back (3 years ago) for use by my little brother. He has moved and now has difficulty "getting it to play". He lives 5 hours away in the wilderness so I can't hook it up for him. I'm sure he has the speakers connected properly, but no matter what source input he connects the CD player, no sound. I was wondering if this integrated had a pass through switch or "jumpers" connecting the pre-amp and amp. Any ideas could help me make him happy!