I replaced the single axle on our Caravel
and both axles on our Excella with new axles.
All three showed excessive tire wear and needed alignment. They were installed using the original holes.
You can do a quick check for tow-in using a long straight edge. Checking for camber can be done on a level surface using a level, but it is a little tricky as you need to measure against the rim, not the tire.
This does not, however, check that the axles are in alignment to the center line of the trailer, and that it will tow in a straight line behind your TV. That can only be done by a good alignment shop.
I use Hewet Alignment in Stockton, CA.