It is mostly component level repair in the house. ALL the newer HDTV
sets REQUIRE special interfaces and factory authorization in order to
even be able to get the service manuals. Plasma sets are all board
level repair via the manufacture, NOT PTS. The least expensive boards
on the Plasma sets are typically $350 authorized servicer cost.

I would expect you will have a significant investment in order to start
doing repairs on anything current technology.