[Welsh Anorak]

Yes, hot-plugging has rendered many a TV's main board beyond repair, though usually this is due to th HDMI inputs.
However the first thing I'd do is to clean or replace the mode switch. This can confuse the mechanism control and cause it to do odd things. Also it's getting on for twenty years old, so power supply capacitors will be showing their age by now.
It doesn't sound like any lasting damage has been done, and it could all be co-incidence.