I'm trying to fix an electric/gas welder for my local garage and I would appreciate some help identifying a semiconductor, please. I'm unable to measure any resistance across any pins.
Its in a TO-18 can and the marking on the top are as follows:
There are also some faint stamped marking on the side: 7524, prefixed with a mark that could be a B or a D.
The can is very badly pitted. This may be just a date stamp !!!