[Adam]

It has the 9-181 main board, model SB5557GC, from 1985. I found this at a thrift store, and I was just so surprised to see a real CRT television at a thrift store that I brought it home.

But it has a lot of issues...

1. The picture was dark, too much color, tint way off, ... At first I thought the controls were bad or dirty because they only worked intermittently or not at all, but that wasn't it, the controls themselves were fine. I finally just re-soldered every joint in the board they are mounted to and cut off the clips on the wires that hook to that board and soldered them all directly on there - and that seems to have fixed it.

2. retrace lines and vertical foldover

First, I noticed those two 150k resistors looked extra-crispy (circled in the first pic - the video output schematic), I replaced them and the filter cap in that 217V source (which is not shown on that schematic) - but this didn't make much difference.

Secondly, I've just been replacing electrolytics in the vertical output circuit (look in the second pic, I circled the ones I replaced) The one I circled in green was the only one that made a difference - got rid of all the retrace lines and most of the foldover.

Now, I can adjust those two controls (with the blue arrows pointing to them in the schematic - one is vert height, the other is just labeled 95V adj) so I have either: not enough vert size, the picture folding over just a little at the bottom, or not enough horizontal width - I can't adjust it in such a way that I have neither of those problems. (The horizontal width control is maxed out) And there is no way to adjust it to get the vertical linearity quite right. In the image of the tv working, it's adjusted so there is not enough vert size, and if you look closely you can see that the v. linearity is off in such a way that the picture is scrunched together vertically at the bottom.

And if I adjust it so there is not enough horizontal width you can see that the picture is sort of wavy at the edges - kind of in the way you get with bad filter caps in the power supply, but it appears to be 'being wavy' too fast to be from 60Hz.

I was almost ready to part this out, but my son said he wanted it for his room, so I'm trying to figure it out.