Can we take this question a step further?
Assuming we can safely attach a scope probe to the cap, and I'm assuming it's part of a high voltage DC power supply. What are we looking for?
Reason I'm asking is a have a Tek 7904 scope and a tube amp with power supply issue. While I don't expect a pure dc output, I'm wondering how much ac in the ps is going to be a problem, if you have 450 volts dc how much ac is ok.
scope has ac and dc coupling, with a max vert input setting of 5v/cm or 50 volts 250 v max input w/ 10 x probe
So like above post, do I have a problem?
And what setting do I want to start with?