Fostex 280 multitracker messed up 4th channel strip: help!

[Ryan Power]

Just received my "new" Fostex 280 four track in the mail yesterday....and all the channel strips work except the 4th! It seems like when recording the input is dead.....playing back works fine, it just seems like the record monitor switching isn't working right (pressing Record Track - 4 and Record button to go into standby).

Any ideas as to what's wrong? I'm getting my money back in full, so if it won't cost much to repair, that's a bonus.

Thanks in advance!