OT(?) : HP1630D Logic Analyser

As I am sure you know, the display on the HP1630 is a raster-scanned CRT monitor. There's conventional-ish video circuitry on the CPU board, using a 6845 as the iming chain. The monitor itself seems to have been 'bought in', not designed by HP. It's the only section for which there isn't a schematic in the service manual (No, I don't have this on paper, but you can download it fro mthe Agilent web site [1] :-)). The monitor looks conventional too. A dism dispaly is most likely to be a failing CRT, but it could be one of the electrode votlages falling. That reminds me -- I should measure and record the voltages in my 1630 to use as a reference if I ever have display problems. When I do this I can post the results so you can see if yours are at elast reasonable. I assume you've done the obvious, namely cleaned the screen. Sorry, but that caught me once... There are some presets o nthe monitor CPB, and those are documetned in the service manual. Some instruments have separate brightness presets for nromal and half-bright text, others have just one control. There's a procedure for setting them up in the manual which needs a photometer (!), but it then goes on to say that if you don't have such an instrument, just do it so it looks good :-). I suspect tweaking these presets might get a bit more life out of an old CRT. If you do need to replace the CRT, cmall monochrome tubes are pretty generic. If it'll fit, has the right deflection angle (90 degrees I think) and heate voltage (most likely 12V or so) then it'll work. I'd ratehr take a CRT from a CCTV monitor or something than raid an HP1630 for parts. [1] YEs, I do prefer manuals on paper, but a web-based manual is much, much better than no manual at all. Agilent should be aplauded for supporting their old instruments in this way. -tony