I have an old airco tig unit and have figured out that it was built by miller.
Serial # HG052868
Stock # 1341-0158

The issue I'm having is that the fine amperage adjustment doesn't work. I have a remote foot peddle and the machine has a switch for the remote and the adjustment on the machine. No matter which way the switch is set (remote or standard) there is no fine adjustment. The High,med and low works it just has no adjustment after that. According to the manual if the circut breaker for the control system is tripped it will only output the lowest setting on the fine adjustment. This seems how its working but I have metered out the circut breaker and its not tripped.

What's up with this thing?

from what I can tell its the same machine as the Dialarc HF.

Thanks in advance