Okay. Sorry for the delay in responding.. According to what "Nacho" said in his post, the device is a Motorola MJ10005. This is a 25A, 400V Darlington Transistor. The current is a little out of our range, but I'm going to take a look today to see what we can offer as a drop-in equivalent.

There's a distributor, Newark Electronics that does have these in stock and they're about $10.00 each. Here's the link..

http://www.newark.com/multicomp/mj10005/bipolar-transistor-npn-400v-to/dp/01H0845

I will respond in the next day or so and let everyone know if I have an equivalent. If I have a close equivalent that's not exact, I'm not going to offer as I don't know the circuit and could potentially create more problems for you.

Best,
Bob