N_Cook wrote:

Blown horn - anything to check on , in the way of ultrasonic oscillation as
went during normal use?
How to break the cab in 2 ? Deep recessed screws tightly bound in dense
plastic. I know , from similar situations, it is quite likely to shear the
screws with the undoing torque required. Soldering iron heater slid over the
end of the long shaft screwdriver to locally melt the plastic ? Dropped
power to it for enough heat but relatively low temp to penetrate the length
of the screw ?

Uh ?

I'm sure I've opened one up no trouble. Take the grille off first.

Graham