LyonsArcade
Well-known member
Issues with 19v1001 B/W Raster Monitor - Space Invaders
Hi guys;
I've got an old Black and White Wells monitor in a space invaders, and it's got two annoying issues. I've recapped it, but the problems persisted after the capkit.
1. The linearity isn't quite right, vertically... the left side of the screen is a little wider than the right, you can't adjust it out, although the two linearity pots DO affect it and make it better, it just never gets all the way done.
2. The screen rolls when you first power it up, for about 5 minutes, then it locks in. You can adjust the hold and make it stop, but then it'll start rolling after it warms up.
So after the capkit, I went back and checked all the resistors in the vertical circuit. All of them checked out as in spec. Then, I replaced all the Mylar caps in that circuit. STILL the same problems. All of the transistors check out.
Any ideas? Could this be something not in the vertical circuit, or could one of those transistors have drifted slightly or something? You can get a manual online that has a nice diagram of the vertical circuit.... also there are two ceramic caps that I didn't change, but since the mylars didn't affect it I figured what's the point.
Any ideas? Anybody ever worked on one of these? It's hard to find info on this monitor.
Hi guys;
I've got an old Black and White Wells monitor in a space invaders, and it's got two annoying issues. I've recapped it, but the problems persisted after the capkit.
1. The linearity isn't quite right, vertically... the left side of the screen is a little wider than the right, you can't adjust it out, although the two linearity pots DO affect it and make it better, it just never gets all the way done.
2. The screen rolls when you first power it up, for about 5 minutes, then it locks in. You can adjust the hold and make it stop, but then it'll start rolling after it warms up.
So after the capkit, I went back and checked all the resistors in the vertical circuit. All of them checked out as in spec. Then, I replaced all the Mylar caps in that circuit. STILL the same problems. All of the transistors check out.
Any ideas? Could this be something not in the vertical circuit, or could one of those transistors have drifted slightly or something? You can get a manual online that has a nice diagram of the vertical circuit.... also there are two ceramic caps that I didn't change, but since the mylars didn't affect it I figured what's the point.
Any ideas? Anybody ever worked on one of these? It's hard to find info on this monitor.