Just for information: My Draftmaster I did work for 1 hour, I did even manage to do a demo plot. Then it died, right before my eyes the display got brighter and brighter and now - nothing when powering on, except a humming sound. I think that I’m responsible for the dead, as the plotter stood in an attic for 20 years, meanwhile power was raised from 220 to 230v (+-10%) in Europe. I realized that the input power can be adjusted between 220 and 240v at the power inlet of the plotter (on the top there is a small stage for a screwdriver, then the cover opens and the rotating think can be taken out)!
Anyhow, had 41 and 83 Volts at the 42 and 85V test points, but always 0 Volts at the +5,-12,+12,+15V test points. I’ve managed to repair the power supply by replacing VR4 and VR5 on the HP Draftmaster I HP7595 Power Supply PCA 7595-060121. I put a scan and some pictures of the lower side of the power pca and uploaded it to http://www.digiwiz.at/penplotter/hp7595-60121_PowerSupply.pdf <http://www.digiwiz.at/penplotter/hp7595-60121_PowerSupply.pdf> (I don’t know how long this file will be there, but it can be put on your page if it could help somebody.) Looking at the service manual of the older 7575 plotter helped me a lot, there is much more information! With nice greetings, Philipp
