G07? Monitor Problem

[daeven]

I just tried to hook up my ArcadeVGA to an old G07 (I think) monitor.  I had my AVGA hooked up to a new WG K7200 with no problems.  Before I disconnected the (apparently dead) game board from the G07, it had a failed test pattern, so I *think* the monitor is good.

Anyway, can someone help me figure out what I have set wrong based on the attached pic of Galaga.  Also, please confirm this is actually a G07.

Thanks!

[daeven]

He is a pic of the circuit board...

Also, it appears that the startfield in Galaga is moving properly (vertical scroll), but the rest of the graphics are scrambled.

As for wiring, I connected cable ground, RGB grounds and ground to the circuit board ground.  Both H and V sync from the AVGA are connected to the single sync connector on the circuit board.  How do I deal with the possibility of the negative/positive sync being wrong?

[OSCAR]

That doesn't look like a GO7 chassis to me, but I'd bet Ken Layton can identify it positively.  To me it looks like your horizontal hold/freq may not be adjusted correctly.  That's the first thing I would start playing with if I had a display that looked like that.

[daeven]

Thanks for the quick reply Oscar.  I kind of figured it was a hold issue, but your post convinced me to search for other pots.  I found one I didn't try before - that fixed it!  The image looks perfect!

I'd still like to know what model this thing is if anyone can help.  It sure looks close to the G07 on Rob Roberts webpage, but I do see some differences.

[OSCAR]

Glad that fixed it!

The white flyback looks similar to the one used on a GO7, but a GO7 has a different video input header layout, and it also doesn't have those trimmer pots next to it.  I also haven't seen a GO7 with all those yellow caps, either.  Sorry I can't tell you what you have, but it surely isn't a GO7 that I've seen before.  The important thing is that you have a good display now!  

[Ken Layton]

It's what Bob Roberts' page identifies as "Eago old style" which is really a very early EYGO.

[daeven]

Thanks.  I may be going to the Bob Roberts website to get a cap kit.  The image is slightly washed out in the center, and the colors seem to be off a bit (that may be adjustable).  But the strangest thing is when you press the player start button to start a game in Galaga, the screen goes dark and then slowly brings the color back in.  I don't think Galaga changes video modes, but I'll try a few other games to see if I can get the same response.