Nanao problems... Any ideas?

[grueinthebox]

Recently acquired a Hang-On upright with a 20" Sega/Nanao monitor (model 200-5072)...  Regardless of whether or not a signal is connected (have tried two boardsets and an ArcadeVGA/hacked monitor cable for source), all I get is slightly diagonal lines across the screen as shown in the pic below, moving up the screen.  Adjustment of various pots makes the lines to get closer together/farther apart or move faster/slower, but nothing makes them go away.  Monitor is running through an isolation transformer, which seems to be outputting proper voltage.

Anyone have any idea what the cause might be?  The screen on this thing has a fair amount of burn-in, so I don't really want to invest too much in fixing it, but if there's something cheap/easy that I can do to make it work, I'll probably run with it.

[Ken Layton]

Looks like the "Screen" control is turned up too high. Your monitor is old enough to need a capkit, too.

[grueinthebox]

Screen control didn't seem to help, so I guess I'll try my hand at a cap kit (if I can find one for this model).  Worst case scenario is I'm out $10 and still have a broken monitor.