So he was able to reset the breaker and tested it good?
Shoot, you may have a short in something downline from the Panel
Any old appliances ie frig freezer that is hardly working or was
ceiling fan any old ones?
Any of the things could have shorted out and cause a direct short.
You won't be able to do this yourself. That's callec a dead short right?
Any of your friends know a sparky (electrician) that can give you a break on the charges. Yes it could be expensive depending what it is
simple as a 2 dollars fuse or as expensive as a few 1000 dollars.
Old wires , wall outlets could be anything at this point
Power guy said you had 240volts at the panel right?