Hi all, i'm currently working on a somewhat ambitious project for my level of electronics knowledge. Basically, I acquired a nonlinear video tape editing control deck from 1983, and i'd like to use the original CRT and buttons and maybe hook up a Pi or something to it and make a faux "battlestation" if you will. I'd like to use as much of the original parts as possible so that it could potentially be put back to its original form.
The CRT assembly is an off the shelf module similar to the ones you might see in old CNC machine controllers. It's made by Dotronix, model BHD500. Seems like they're still around but I have not been able to find a datasheet for this unit. The issue i'm having is that I don't know what kind of video signal this monitor is expecting. I looked at specs for other similar models of monitor and it seems to indicate that it would either be standard composite or some kind of TTL signal. The monitor board has an edge connector with 6 pins in use, one pin has two of the same green wires running to it. Red and black are the + and - 12v in (i assume 12v, seems to power up fine on my ultra high end lab grade ATX power supply....). Yellow, orange, and one of the greens run to a potentiometer mounted outside the chassis. The other green wire and white wire run out of the monitor and I assume are the signal inputs.
At this point, I have been able to get the monitor powered up, can hear HV and can see the heaters glowing in the tube. However I have not been able to get a raster or any picture. I've tried feeding it a composite signal since there are only two wires leaving the board that aren't power, but this only results in the pitch of the HV changing and no image. I have gone through and tested all electrolytic caps and found one with high ESR so changed it, the others all tested within spec. This did not have any effect. But without knowing if i'm even feeding it a signal it likes i don't really know what to do next...
Some more context on the machine: This control unit seems to be designed to connect to a rack of equipment which would supply power and other signals. The unit has a single dsub style connector mounted on an interface card which connects the jog wheels and control buttons. The 4 wires from the monitor connect to this board but look to be passed straight through to the dsub connector. I have bypassed this board at the moment as I don't think it has anything to do with controlling the monitor, but I could be wrong. I've attached photos of everything for context.
Any help is appreciated as, I really don't know what i'm doing at this point (I am familiar with working around CRTs and safety precautions etc but not the ins and outs of video signals).