I have an old Tektronix 2235 scope that works, although the trace is a bit fuzzy and the controls a little iffy.
(s/n: 202176)
I have checked over the PSU voltages which seem OK.
The unit is pretty clean and tidy with a little scorching around the focus chain resistors (now replaced with 1w metal film as some were out of range) and R266-271 (not replaced, as these meter up OK and look pretty good). I have replaced the 3 RIFA caps in the PSU that were in various stages of breakdown.
No visible improvement to the display yet - so I was tending towards replacing the 4 SPRAGUE 3000V plastic capacitors (10nf - C855,C975,C976 & C979): my question is: would these be suitable replacements, or does anyone know of better:
KEMET C4C Metallised Polypropylene Film Capacitor, 3kV dc, ±5%, 10nF, Through Hole (C4CAYUB2100AA0J)
Many thanks for any pointers on this.