SWTPC TVT-II

Hey everyone, I'm a fairly middle-weight collector based in Squamish, BC. I have about 70 machines total, a few of which are projects that I'm seeking advice/help on. One of them is an SWTPC TVT-II CT-1024 terminal. I bought it a couple of months ago, complete on ebay. I've tried to read as much documentation on these as I can find, but there are a few things I can't figure out. I've posted a few videos of it -- including this one: https://www.youtube.com/watch?v=c2rX10-m8GQ Initially when I turned it on, I got just garbled screen. The first monitor I attempted to hook up to was my Apple III, which apparently can't handle it at all. Then I went to my Commodore 1702 and 1084, and I can adjust things enough to make out a picture and characters, but it's repeated several times, as you can see in the video. On the first few powerups I'd see the occasional flickering of a full field of questionmarks, but it wouldn't stay. I learned about the voltage trimmer on the PSU and have trimmed it to 5V exactly, and now when I turn the unit on, the field of question marks comes up and stays. There is a switch I've discovered (none of them are labelled) that causes that field to disappear. I think this puts the unit into terminal mode. The keyboard is connected to the serial card (I think there is a connector on the motherboard where it could go also if you didn't have that). I also played with some trimmers on the motherboard that adjust horizontal position and so on. Anyway, what you see in the videos up to the most recent one is the most I can make it do. It doesn't seem to respond to keystrokes, and the documentation I have is limited or a bit over my head. Mainly I'd like to figure out why the screen is so messed up. Much appreciated if there are any of you out there familiar with these old timers and would have an idea where to begin looking. Brad