[Electronic M]

Status update: I've taken the set apart, cataloged all the caps in it to change for reliability (I'm going to try to make a large capacitor restock order in the next couple of days), and changed all the caps that I can with of my current cap stock.
Right now all the cosmetic panels are off of it.

The caps I changed so far are the plastic tubular caps in the convergence, sweep, under the CRT, and the power regulator. I also changed a couple of lytics on the sweep side.
Before:After






In the last before shot the old lytics appear to be replacements from decades ago. Most of the plastic tubular caps in the horizontal section had been cut then the leads touched together and soldered (kind of a shoddy way to do it) which suggests someone was clumsily looking for a bad cap in that stage. Theres what appears to be an extra pot in the below picture, but otherwise it doesn't appear to have seen much work from previous techs.



The CRT is labeled as EIA274 which crosses to RCA. Your monitor is a CYB, but that thread is mostly about the CYA which was an older model. The CYB line likely never had the Hitatchi CRT.



After changing caps nothing had changed so on a hunch I clipped a newer used lytic in parallel with the 1500uF 50V can and the hum disappeared from the video(sync is lousy though). That can and the rest of the lytics will be on order soon. Until then this project will be on hold. It will probably be sometime next week when I get the parts I need for work to proceed.