[Tgace459]

Simple enough to check be using a dc voltmeter connected from transformer frame + to radio chassis - with the transformer isolated from the chassis. If it is shorted replace it as it can destroy the rectifier tube and power transformer if left shorted to the chassis. Other things to have a look at are the 41 socket (shorts from pins 2 or 3 to ground) bad rubber connecting to those pins. Bad cap from pin 2 to ground or tone sw.

Based on the sparking Im getting I believe the transformer case has some current going through it....or the chassis...