HP 1746A Oscilloscope trace horizontal position off to the left
 

I have a 1746A that seems to trigger correctly etc but the horizontal
position of both traces is way off to the left. The horizontal
position knob if moved as far as possible will bring one edge of the
traces to about mid screen.

Also if the traces are moved off of the vertical center axis they
start going slightly nonlinear in that they start to curve up or down
on the edges closest to the left of the screen. If the traces are
moved up they curve up. If moved down they curve down.

Any thoughts or suggestions as where to start.

Thanks