SNES Kiosk CRT Issue

[D 4213]

Hi everyone, total newbie here, but I am at my wit's end with the CRT monitor on my SNES display kiosk. It developed a very violent side to side shake/wave upon being turned on one day. Before this, the image was perfectly clear. I've opened it up with a friend who's a little more electronically savvy and we couldn't see any components that looked burnt out and no capacitors that were bulging or leaking. We tested the capacitors and they all seemed fine. Is there some stupid simple reason why this would suddenly happen?

Video of unit running:
http://imgur.com/a/Z2akJmp

Thanks in advance for any guidance you guys can provide!

[nem]

It's not syncing. You've double checked that it's not the console or the video cable to the monitor?