Is there a simple test I can do to tell if the OT is blown, or maybe test a few caps or resistors?
Yes! Yes there is:http://www.premierguitar.com/Magazine/Issue/2007/Apr/The_Super_Secret_Transformer_Tester.aspx
Article by the venerable RG Keen.
This is very good article.And the trick that mention in it are really useful and cool.