I have no time base. I think I sold (more likely "loaned") it years ago. Just bought one off ebay for $20 shipped. We'll see. With the 7A18 in either slot, I can get ch1 and ch2 dots and the voltage scale at the top of the screen (after a lot of fiddling).
It's very intermittent and most of the time the only thing on the screen is the garbled dashes in the picture and only with the beam finder pushed or locked.
I pulled the side covers off and everything looks shiny and new.
I can't "make" it work. It just pops to life at random.
Sometimes just a dot...sometimes just the volt/div...sometimes the garbled dashes which are actually numbers (either 1s or 4s) that are usually too far up the x scale to see without the beam finder.
And once, the whole scope seemed to just function normally, like magic.
Pretty tidy inside. Most of the boards are clearly labeled and easy to get at and service.
If I can find what is causing the intermittent operation of the display, diaging the rest of the scope will be possible.