I don't know... I tried hooking the A gate output on the back to another oscilloscope (a cheap USB one) as was recommended in the "Troubleshooting Your Oscilloscope" manual and nothing.
I also now have no dot at all, and back when I did, the intensity knob just messed with the focus, although not as much as the actual focus knob. Beam finder still makes the dot show up just fine.
It feels like things are deteriorating... I'm thinking of trying to find a local hobbyist who might help. Any suggestions on where to look?