You can begin troubleshooting the vertical amplifier by chacking voltages at specified test points. They will tell us a lot.
Go to and download the 454A manual, not the operator manual. It will have schematics and board layout diagrams near the end of the manual.
Go to schematic #4 and measure voltages, referenced to chassis ground.
To answer your question from the video, I belive the beam finder works by disconnecting a direct -12V rail from the vertical amplofier, and instead putting it through a 750 ohm resistor. This will reduce the vertical amplifier's deflection range ability, thus you can see the beam when using beam finder. That is the whole point of the beamfinder function anyway, to get the beam in the display.
When the beamfinder is activated, it is in the lower half of the display, indicating the beam is being deflected down out of the display. There is no vertical scretching of the beam, the beam is simply hitting of the phosphors off of the display screen and reflecting light inside the tube.
Again, use a DMM to measure voltages.
Recommend spots:
Junction between C369 and L369
L343 (any side is fine for just sinple voltage measurements)
Junction between VR339 and R339
Junction between R311 and R312
Base of Q424
Base of Q324
Base of Q474 and Q347
Emitter of Q414 and Q314
Thise voltages will help us discover the problem.
Also I doubt it's user error. Cal lights are likely from bad switch contacts as it looks like the knobs are indeed in the dented position.
Benjamin
Benjamin Badrakh