Are you selling it b/c you couldn't fix it? I had the same problem with my Betson and I sent it back. Weirdly enough I'm moving to Macon in a month and need a new monitor for my Slikstick cab and could use this, but I guess not if it has the same problems.
Did you contact the company? Betson told me that a problem like that (mine was just like yours) is a factory issue and cannot be fixed, hence the return.
Let me know what you ended up doing.