WG6100 on Star Wars Monitor/Board Adjustments? X-Size maxed.

Madaracs

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WG6100 on Star Wars Monitor/Board Adjustments? X-Size maxed.

Here's the situation: The low voltage section on my deflection board burned out twice. Long story short I had to wait for a faulty LV2000 board to come back from Jeff Hendrix which he graciously fixed. He rocks.

In the meantime, it was suggested that one of the chassis transistors may be causing a fault on my deflection board. I replaced all of the "bottle-cap style" 2N3716 & 2N3792 transistors on the WG6100 chassis and I ordered a different deflection board (same model P314 minus the Atari input protection board that my original had) which had a new LV2000 installed on it.

After the repair and putting in the new deflection board, everything worked swimmingly when I started it up except that the screen size had shrunk a bit. Here is an example image:

sw-screen-sm.jpg


I put the game into test and adjusted the Y-Size and X-Size pots on the AVG board.

adjust-x-y-size.jpg


I had to max out the X-Size pot to have it fill the screen. So I decided to back it off a bit just because I don't know if:

a. That might be over-driving the X-Size on the AVG board or something?
b. I had to adjust it to make the text look right.

The LV2000 voltage settings are -26.04 and +26.08.

Ultimately I settled on something a screen size slightly smaller than had previously been adjusted to. I can still clearly see the alignment dots on the screen as seen in this example:

sw-blue-dots.jpg


My issue is:

Now when the death star explodes and/or when the scrolling text goes by in attract mode it's getting kind of bunched up on the right and left side of the screen. Not terrible but noticeable. Also, I'm not sure I'm supposed to see the blue dots.


My questions are:

1. Is the X-Size pot being maxed a bad thing?

2. Are there other adjustments on the WG6100 I can make (Purity rings?) to fully utilize my monitor's landscape in both X and Y directions? Would upping the voltage slightly on the LV2000 help?

3. Am I supposed to see the blue dots?


I realize this might not be the exact spot for this... Could be a monitor issue could be a board issue... I suspect monitor so I'm puttin' it out here first. :)
 
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Your high voltage could be off. I am guessing you don't have a HV probe to measure it but you could measure your B+ and see where it's at. Most people tend to adjust the picture too large anyway and no, seeing the blue dots is not a bad thing. They should be about 3/4" in from the corners of the tube.

edit: looking at the red grid, I would say it looks about right.
 
I'm guessing HV too.

Yes you should see the blue dots (it is specified in the manuals). In fact I always adjust the size on SW set-ups using these instead of the test-screens because if you would do it with the test screens the picture is too large.

You should not however see black between the guns on the left and right and the edge on the screen as there seems to be now. If you can't get the H-size any larger there has to be something wrong further down the system. I think the LV voltages are OK like that.

In my experience if the H-size is too small, you will get what I would call "walling" at death star explosions or it might looks a bit like a fold-over.

Does it look like this? :
http://youtu.be/aePHZsifvIA

This is a WG6100 running on a 25" low-res tube. I never got it fixes regretfully...
 
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Looking back at that video it seems to me there is some wrong offset on that one. I think the right side shows black between the edge of the gun and the edge of the screen, while the left sized is "squashed".
 
I agree with Arc. When the B+ more than 200 VDC goes up the size of the picture goes down

Andrew
 
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So here's the interesting thing.

As I mentioned before, the deflection board that is in the machine is the one that I just bought. And I repaired my original deflection board last night but had not put it back in my machine yet.

This evening I did. The picture went back to normal. I had to reverse my X and Y settings by nearly half a turn each on the SW AVG pots. No more walling effect.

Something about the two deflection boards are different. My voltages on the LV2000s are almost identical.

So now I'm thinking I might want to test all of the resistors and transistors on the deflection board I pulled to see if one is bad somewhere.

Could I have a cap that's not workin' so good anymore on that new board?
 
Check B+ on both boards.

> Here is a trick for adjusting R918 without an HV probe. Hook up power to the monitor (but without any input signals from the game board) and let it warm up for about 10 minutes. Now measure the Video B+ voltage either at pin 5 of P900 on the HV board, or at J501 on the neck board (refer to your schematics). Adjust the HV so the B+ is 181v DC. Since the Video B+ and the 19.5 kV outputs are linked together, you will get the HV pretty close to perfect.
 
Check B+ on both boards.

> Here is a trick for adjusting R918 without an HV probe. Hook up power to the monitor (but without any input signals from the game board) and let it warm up for about 10 minutes. Now measure the Video B+ voltage either at pin 5 of P900 on the HV board, or at J501 on the neck board (refer to your schematics). Adjust the HV so the B+ is 181v DC. Since the Video B+ and the 19.5 kV outputs are linked together, you will get the HV pretty close to perfect.

Cool advice, cheers :)
 
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