Hello all!
I have an HP-85 (well, 2 in fact, but one had the simple fuse problem) with another power supply problem. I picked them up as non-working from a highschool that received them as a donation from Boston University (it says so on the case, in a message burned with the soldering iron). It appears that someone has forgot to set the voltage switch and plugged them in (line voltage here is 230v). So one of them had both fuses blown (mains and the one inside the power supply), the other had only blown the mains. Inside the PS it was the switching transistor (I think) that protected the fuse by destroing itself
along with its driver transistor.
The transistor used for switching is a 2N6317 and the other one (I think it's its driver) is marked with 113M and 3-449. I know it's a PNP one (from measuring the one in the working PS), but not much more. I have seen a schematic in Dave's film, but I couldn't find it. All I found is the HP-85 repair course that doesn't include power supply schematics. Can anybody point me to that schematic diagram?
Since I don't have those particular transistors (well, I'm not even sure what the other one is), I was thinking if maybe they could be replaced either with 2 equivalents or maybe both of them with a single MOSFET.
Thank you in advance