I didn't actually mean glue the knob to the shaft, the epoxy comment meant putting a couple of little (ie, small enough to fit through the splines on the plastic) blobs of epoxy on the shaft, leaving it to *set*, then sliding the control onto it - ie, *not* gluing the knob on.

If the display has gone dead I suspect you've managed to pull the switch off the PCB enough that it's snapped the filler neck on the VFD. Ouch.

Hugo