I've posted a collection of photos that are part of my intake inspection process. The scope is still out in the garage, but now I've given it a brief once-over and recorded what I saw. The album is
/g/TekScopes/album?id=263746The only obvious damage I found was already noted by the previous owner: a vaporized resistor (R760) in the +500 V power supply. In this serial number range that resistor is only 10 Ohms, so I suspect that it is there as a sacrificial protective element, to prevent too much current from flowing and damaging other components.
I don't know when that resistor sacrificed itself, but according to the previous owner it could easily have been 40 years ago. I can't very well check the resistor to see if it's value has drifted from spec (it's value has certainly drifted, all over the inside of the scope and elsewhere, I'm sure!) and other components in the same circuit are as likely to have drifted since the incident as before it, so I doubt that I can come to any conclusions about the cause of the failure. My plan, however, is to work my way outward from the point of failure and replace anything that doesn't measure to spec. I expect this to be a slow process, and for a lot of things to need replacing.
I ordered a fresh spool of silver solder.
-- Jeff Dutky
