Korg ih Harmonizer

[frisco3063]

Hello, group. I was hoping someone could help me with a Korg Harmonizer that I bought used on ebay. I downloaded the manual, but the buttons to change modes do not respond. I can't even get the unit in to learn mode, so that I can change the MIDI channel and so forth. If anyone has owned/operated this unit in the past, does it sound like I'm doing something wrong, here.

Thank you for any help

frisco3063