B&K 465 weak voltage
 

I've had my B&K 465 for about 8 years now. It's actually been a really good tube tester and I've used it to rejuvenate quite a few tubes. I noticed that anytime G2 voltage is 50 volts on a tube it tests very bad. So today on a hunch I used the tube pin out and checked the G2 voltage what should be 50 volts was only 20. I think the original components are starting to fail. I attached the schematic below. Judging from the drawing other than the Transformer they seem to be what makes up the main power supply for the entire tester. Am I right in thinking that if I replace the two 5 microfarad capacitors I should be able to bring this thing back ? To me they seem like they're the main filters and maybe they're getting weak? Or am I more likely to have to go after the 4 Diodes just before them.

There's not that much to the unit, so while you're replacing the caps on general principles, it would be quick and easy to check the 100 ohm and 470k ohm resistors. I would feel dumb if I didn't take the opportunity.

Also, C-3 and C-4 (50 mfd) and R9 and R10.

Well unless Im reading the schematic wrong C3 and C4 seem like they're just for rejuvenating a tube. I don't mind replacing them. But I wanted to see if I can get the voltage back into spec before doing the rest of the recap. What do you think?

Fine to do the ones in the power supply first and then check. My thought though is they're all the same age, and it's not a lot of parts, so why not bring them all up to date?

I totally agree with you. My only concern would be if the transformer was on its way out or something like that. Then I'd feel foolish rebuilding the whole thing to find out it still doesn't work.