On Sun, 19 Mar 2017 16:34:43 +1100, Sylvia Else wrote:

On 18/03/2017 8:27 PM, Sylvia Else wrote:
The smoke escaped from my old oscilloscope today. I've determined that
it came out of R740, to the bottom right of the circuit diagram.

https://www.dropbox.com/s/9053dnyr0izv88r/XAMP.PDF?dl=0

This is because T711 has shorted out.

Not very surprisingly I cannot source a replacement BF472, so I need to
find a substitute.

This is the final X-axis amplifier, so we're not talking high
frequencies. Is it likely to be sensitive to the particular transistor
characteristics?

Sylvia.

Hmm....

They may have supplied a circuit diagram and board layouts in the user
manual, but this thing is clearly not designed to be repaired. There are
multiple wires soldered directly to the boards, including some of those
from the power transformer, and to the side of the board that's not
readily accessible until after they're been desoldered. How did they
assemble this thing? With some kind of right-angled soldering iron?

I'm x-posting this to a more appropriate forum, Sylvia, the guys there
will be better able to assist you with this...