Arcade monitor wobble? (bad ground?)

[superlime]

Just finished putting cap kits in both the 20-EZVs for my Nintendo VS cab, and I've still got a really bad wobble of the screen.  It seems to be both a side to side (horizontal) and up and down (vertical) wobble, so I'm not sure what could be the problem.  I'm thinking possibly bad ground, and saw something in the FAQ about:

Monitor Interference fix as provided by Ken Layton:

If the pattern is "herringbone" (as the experts call it) which newbies would call a fine "worm wiggle" you need to connect a jumper wire on your power supply between the "Frame Ground" terminal and the DC output Ground terminal.

The FG terminal on the power supply should get jumpered to the either one of the GND terminals on the power supply. FYI those GND terminals are the DC output ground.

Think that might be the same thing I'm seeing?  I'd try the fix right now, but the cab's at work and I'm at home..  Just thought I'd get some further input before messing with it.

One odd thing I noticed when capping the monitors was that there was a brown cable with a socket on it (only one line to the socket) that was bundled with the monitor's power cable.  For both monitors this wasn't plugged in to anything and was just hanging out back there.  I didn't at the time bother tracing the line, but might this be a ground connection that should be plugged in and might help with the 'Herringbone' I think I'm seeing?

Thanks in advance,
-superlime

[Hiub1]

So it's a fine wiggle? I guess go with what Ken said. If not, have you tried adjusting the pots a bit? I just started messing around with that same monitor you have, and at first the picture was awful but now it looks great after a bit of tweaking! Just make sure that you find all the pots within the board, there are a couple of hidden ones.

[superlime]

I've done quite a bit of tweaking of the pots...  Even mucked about a bit with the convergence on the neck of the tube.  Any idea what the one you finally found was labelled?  I saw some kinda deep in on the board when I was installing the cap kit, but I'm not sure I've tweaked those while the thing was on.

-superlime

[Hiub1]

Well, there are 2 on the board that are kind of tucked away. One of them is the Horizontal sync, and then there is another black one that I have no idea what it does. Also, there are 2 right on the flyback cage, they are inside 2 little holes that you have to reach with a screwdriver to get to. Those were focus and something like a brightness control.

[Ken Layton]

Remember that these Sanyo monitors operate on 100 volts AC not 120. They must be powered through an isolation transformer.

The two small trimpots on the monitor's main board are "Horizontal Hold" and "Sub-Brightness". The white shafts on the flyback are "Focus" and "Screen" (coarse brightness).

The brown cable with a connector on it is the shielded audio (line level) input to the monitor's amplifier board. The red and white wires with the two pin white connector is the audio output to the cabinet mounted speaker.

Always check this chassis for bad solder joints. Remember that there are TWO capacitor kits that need to be done on this model: one for the video portion and one for the amplifier board. Did you do both? Tell me you said yes.

The giant main filter capacitor is NEVER included in any capacitor kits. It sounds to me like this is your source of 'wobble'. You can buy this capacitor from Bob Roberts.

[superlime]

Guh.  So me being the impatiant idiot I am, tried just plugging the monitor directly in to 120VAC without the isolation transformer.  I've blown out something more than just the fuse, as I just wiped out the fuse from the second monitor testing that theory. 

Plus side: This forces me to replace the one of the pair that had ugly burn in.

Minus side: No clue where to find another.

I actually had no idea about the amplifier board one, makes sense though.  I'll poke around for one, as well as figure out the size on the giant main filter one to grab from Bob roberts.

After I clear my workbench off in my office again, I'll take apart the blown one..  Maybe it's not as bad as I think.

Thanks for the info, even if I read it too late.
-superlime

[Ken Layton]

Be advised that if you blew out the voltage regulator IC on the monitor main board, it's a very hard-to-find component that was discontinued 20 years ago.