I recently acquired a Durst Pictograph off eBay but unfortunately it turned out to suffer from a number of problems. While I did manage to get a refund from the seller, he told me to just keep the enlarger, leaving me with three options as I see it: attempt to repair it, find a new head for it, or throw the whole thing out. I think it may be worth fixing but I'm not sure if it's possible nor if it will be worth the expense of doing so. The controller (identical to that of a Pictochrom) has some defective buttons on it that make setting some functions impossible. Some of the numeric keys do not work, the time button doesn't work, etc. Assuming I can find replacement parts or a new controller (easier said than done), I figure that will be a relatively simple fix. The most concerning issue, however, is with the closed loop system itself. When set for a hard grade (such as grade 5) the head will "chatter" and the controller returns a "closed loop error" instructing me to check the lamp, which is perfectly fine. Removing the cover for the head shows that the motor is trying to push the filter further into the light path, even though it's already fully slotted in. Any ideas on what's going on or how I might fix it? Thanks!