Remote control issue

Hi All, my happijac remote has a problem I need a new one, I called Northstar vans to get a new one, but they are saying the new remotes are not compatable with the old mother board and there for I need a new mother board as well. Is does anyone know if the remotes on ebay will be compatable with the old mother boards or where I can buy a old remote that should be compatable with the old board?

Minster