glad to hear you fixed it... I didn't (yet)... That looks really curious, why the heck would an encoder signal be connected to the ribbon going to the screen buttons ????
But indeed, if you don't need one of the keyboard PCBs and/or parts of it anymore (I believe the encoders are the same as on mine), I'd like to buy them from you. Please contact me at philippe.annet 'at' hotmail.com , I don't think this is the right place for trading...
Hi, I have found that the digital encoder pots on these digital scopes are just like potentiometers in that the have a wiping contact which goes round 360 deg, like pots they get dirty. I have used an electronics switch cleaner aerosole to spray inside the pots and this cured the problem. Spray into the opening on the pots and turn the pot round half a dozen times, wait a few minutes until the cleaner dries off then turn the scope on and check the operation. I usually removed the front panel to do this operation. I worked at the University of Canterbury in Christchurch New Zealand for 42 years, I ran the undergrad electronics teaching laboratory in the dept of Electronics and Computer Engineering. I had 33 HP 54600A Oscilloscopes in the lab to look after. Don't use an aerosole switch cleaner that has a lubricant in it this will attract dust and dirt to stick to the contacts.
I am having a similar issue with both of my 54616C oscilloscopes. The knobs for time and voltage (both channels) on both oscilloscopes generate unstable values when turning the knobs. Two clicks in the same direction may produce one step up followed by one step down. This is really annoying in an otherwise nice piece of equipment. Clearly the rotary encoders are producing unstable values. They are either worn or dirty.
Is it possible to get schematics of the scope?
Is it possible to get manufacturer and part no. information on these rotary encoders?