Help identifying D1047 transistor (pic included)
Here is a datasheet for a 2SD1047, which will almost certainly be for this device.

Searching for "D1047 datasheet" finds a few more similar datasheets, it's a NPN power transistor. Certainly replaceable with a similar component from e.g. Farnell, Digikey, etc - they will have many options.

Of course, you can always order an exact replacement if you should wish.