Miller big blue 300 pro hlp 23

[jpeters]

Got this unit in for repair. It had a hlp20 error. Replaced the controller and now have hlp 23 very low output on generator and welder. Brushes and slip rings are ok. I only see abut 12 vdc at the field... I am wondering about the scr`s. The gate leads check open on one scr in the dual scr package. Not sure how to test these accurately. I have not scoped the gate leads yet but that firing signal comes from the controller that I replaced so IDK! anyone here know about these or have a source for a service manual? This one has the Kubota engine.

[1997CST]

You haven't explained why you jumped to replacing PC1 so quickly without a service manual. Anyways F1 will cause low output on both 110v plugs and OCV. There are steps to jumper PC1 to find out if your SCR's are bad but so much to check before that.