WTD: manual for GE PJ-400 light valve projector

[Opcom]

I'm revisiting my old PJ-400 GE light valve video projector.

Does anyone else have one of these pre-Talaria units?

The older 'pre-Talaria' monochrome and color PJ-xxx units are not the big tabletop units like the Talaria, but a slimmer projection 'head' mounted to the top of a heavy rack full of circuit modules with tubes and transistors IIRC. The head can be removed and positioned as necessary to shoot at the screen. Mine has about a 10FT cable.

It powers up partially and the Xenon lamp can be turned on, but it will not make an image with the light valve tube, even though I have had it powered on and pumping down for 3-4 days, as recommended by persons who worked with them. The Light Valve tube is intact. It's probably some electrical fault in one or more of the several modules.

It is much more than a CRT with a lens, the light valve operates by etching ridges into an oil film in front of Schlieren optics through which a 1KW Xenon lamp shines. On the other side a lens projects the image on a screen. The oil film is continually refreshed from a reservoir as it is carried on a magnetically driven rotating glass disk all inside the tube. The tube has a continuously operating ion pump and the scanning of the raster is electrostatic.

Its workings can all be seen through the clear light valve tube body. Because of this highly coordinated technology, there are many electrical interlocks that prevent the startup process from proceeding past any fault. It does not seem to have fault indicators.

I don't have a recent picture but will try to take some - got it before digital cameras were a thing. It's a rescue from a closed business, found near the building's dumpster in the 1980s. A miracle to find it. Maybe a miracle to fix it. It deserves to be fixed!