XM-501 vertical collapse

[paigeoliver]

I was adjusting the monitor in my newly acquired "Drop Zone 4" when it went into a vertical collapse, I was adjusting the screen size control when this happened.

The whole game is squished into an area about a half inch tall, I can adjust this height as low as a single line tall, or as tall as a half inch.

Any thoughts on which part might have failed?

Also, when I have it about a half inch tall and drop a bomb it looks like the bomb goes up and down up and down until it hits, like the image is folded over a half dozen times.


Note, the Xm-501 is a black and white monitor.

[Ken Layton]

Possibly the vert size pot gone bad. More likely dried out caps or cold solder joints particularly around the connector pins around the outer perimeter of the board.