I have a NEC Accusync 700 CRT monitor that I bought new in box a few years ago (a bit expensive, but hey).

Everything displayed on it has a greenish tint now. It started out flickering between normal and greenish, and now it's always greenish.

The on-screen display to adjust brightness/contrast/etc. displays perfectly in normal colors, so it isn't the tube/guns/etc. but something involving the VGA signal.

I have a Sun Ultra 5 that I plugged it into recently. That machine has a "native" VGA port (no adapter required) and I don't think it uses sync-on-green. Nevertheless, if it does, could I have fried something?

I also have a PS/2 30-286 that has a more thorough POST than a modern machine, and when I power it on plugged into this monitor I get some beep tones, and an error code 2401 as if it can tell something electrical is wrong.

Is it likely enough that it's the cable that I should look into safely working on CRTs enough to replace the cable? (It's an old-style hard-wired one not detachable like on some of the last CRTs or an LCD). Whenever coronavirus is over enough, there's a hackerspace near me with a lot of mechanically minded people I could get help from (they also helped me successfully re-cap a Macintosh LC II board). And any suggestions on where to find a cable as it seems difficult to search for.

Could I have blown a fuse?

Or, is everything a coincidence and it's just other electrical components (capacitors, etc.) worn out?