[TinCanAlley]

Well I want to start work on another green monochrome monitor, but this one has nothing I can find on the internet and no schematics. I did manage to trace the socket board on the neck and found it has the exact same pins, in the same order, as my IBM, TRS-80 and RCA B&W TV. That means socket CR7 from the BK tester will work, but I don't think there is a problem with the CRT, it has to be in one of the circuits.

When turned on, it gets not raster, even at the highest settings. However, it does have a collapsing raster when turned off. I'm assuming that's some kind of bleed off of HV?

Now this monitor does differ from the IBM in that it has both horizontal and vertical as noted on the circuit board. That means it should produce a raster under higher brightness settings. The know on the front is all the way up and so is the subbright on the board. I don't know what the resistance for those is supposed to be, so testing for anything other than being open wouldn't help much.

So this leads me to 2 questions. Since my DMM goes up to 600V, and this monitor (other than the HV) should be higher than that, can I use it to check all but the HV voltages at the CRT? Also, what areas should I pay particular attention to?

Oh, and there is a composite lead from the power board to the CRT neck board that I have never seen before. I don't know what it is providing as these types aren't used for power, but RF.

Lastly, the IBM has no horizontal or vertical, so the monochrome adapter provides those on pins in the connector plug. Since this has those circuits, is that video adapter useless on a monitor like this, or will it ignore those signals? I beginning to wonder if this monitor is from some kind of data terminal. Maybe it wasn't designed for the PC.

I'm attaching some pics that might be of use/interest.