I would suggest probably the CRT flashing over?, a fairly common Trinitron problem - however, your 'mistake' was cleaning it, particularly cleaning it before making sure the set was 100% functional.
You say you greased the anode cap?, what kind of grease did you use? - and what was wrong with the factory grease?.
As a TV engineer for 46 years I saw countless repairs coming in, where the customers had cleaned it, and the set no longer worked, or had a new fault. I even had one B&W set (a Thorn 950 as I recall?), where the customer had cleaned it, then tightened down all the 'loose screws' in the IF transformers!!
Pointless cleaning inside a TV isn't generally a good idea (it doesn't help anything), unless there's a specific reason for doing it, such as a need to repair the set, where cleaning allows you to see what you're doing (and helps keep you cleaner).
I'm also quite bemused someone 'bought' a CRT TV
- you can't usually give them away - and we tried, many times.