Museum of the Game® & International Arcade Museum® Forums

I've been scratching my head on this for a while and figured it's time to see if someone has any ideas. There is wave, or rather a shift, on the top of the screen.

20250212_150626b.jpg 20250212_150543b.jpg

I thought maybe it was something with the TPG, so I hooked the monitor to a game. The artifact is still there.

20250212_154625b.jpg 20250212_154655b.jpg

When in grid pattern on the TPG, the vertical lines are wavy.

20250212_191254b.jpg

I can minimize this wave if I turn down the contrast. But it doesn't completely go away.

Here are the details:

This is a 19k7000 P447d chassis married (or rather first date) to a TV tube https://tubular.atomized.org/tube/A48AFN22X

The chassis has had a full recap kit (with a new filter cap), reflowed, and has the original flyback.

The tube has clean guns, Vertical Ohm 13.0, Vertical Inductance 27.3mH, Horizontal 4.8 Ohm, Horizontal Inductance 3.2mH

20250210_120740b.jpg 20250210_120038.jpg 20250210_120016.jpg

I read that this might be a grounding problem. I have 128 Ohm between the aquadag and the dag wire. The dag wire is wrapped around the monitor frame and is hooked up to the neck board. The neck board is also grounded to the chassis frame. There is continuity from the dag wire to the neck board. The monitor frame is also connected to the grounding strap inside my Joust cabinet. Again, there is continuity between the monitor frame and the grounding strap.

Another possible cause I read about is a sync issue. I have the the TPG hooked up to separated vertical and horizonal syncs.
20250212_193653b.jpg 20250212_193658b.jpg

The game in the picture above was hooked up using composite sync on Pin 10 of the chassis.

If anyone has any ideas, I'd love to hear them.
Thanks.
Back
Top Bottom