smd and acc board-test transistors in situ?

[tom.jelly]

Is it possible to test transistors on the smd or acc boards while they are mounted? if so, how?
Is is correct that all three axis' smd boards from the same machine are interchangeable?
The acc board I have has had some transistors replaced in the past. Each has one steel screw, soldered to its trace,
and one nylon screw, is this correct?

TIA

tom

[bartL]

Tom,
When I was doing a retrofit on my machine I checked the transistors on all SMD boards too. I didn't took them off since they were soldered. But you can't really thrust the readout you'll get on your DMM. But you can compare the value with the others and if one reads different that one probably will be wrong. But those will probably be all good.
The smd board are the same and they are interchangeable. I had one bad axis on my machine and swapped those boards to check if the problem was on the SMD or somewhere else.
The transistors you decribed on your acc are correct, they are on mine too.

[tom.jelly]

Thanks, I thought maybe someone ran out of metal screws!

t