Defender Decoder questions

[MYX]

Does anyone have experience with Defender.
Dabone put me on track with Bob Roberts to replace my video decoders. I e-mailed Bob this question but I thought I would put it up here as well.
Upright uses Decoders 1 & 3
Cocktai uses Decoders 2 & 3.
What is the difference?

Is this why my image will not fill the screen from top to bottom? Left to right is just fine.

Also Occasionally I get magenta flashes. Everything that should be black will flash to magenta. This innitially would only happen once and a while for a few seconds. Now it happens most of the time right at start up. Bob thought it might be a monitor issue. Does anyone work with monitors that would know what is happening?

Does this belong on the monitor page?

Thanks all.

[dabone]

The cocktail flips the screen for each player.
(I've got one.  )

The upright does not.
(I don't have one )


Not filling the screen vertically, most likely you need to adjust your vsize on the monitor.

The color issue sounds like the monitor also.

What kind of monitor and have you done a cap kit recently?
Reflowed the solder joints on the input pins?


Later,
dabone

[fredster]

I'd guess that when you put in the new roms, it changed your video output slightly.

I'm betting it's a WG4600 or WG4900 monitor. You will have to adjust the vertical on the back of the monitor.

Did you try that? Or was the pot moved so far it wouldn't adjust anymore?

The magenta flashes sounds to me like a board problem (ram).

[MYX]

Though this is not scientific, I have reciently done a cap kit on my Ms. Pac machine. the caps in the Defender monitor ( yes it is a 4900) are the same Black & Blue colors as the caps I just used. so I believe it to be a somewhat new kit. I have a 4900 kit I can use.

I have tried sizing the monitor but when it gets above a certain point the picture rips. It is just under maxed prior to ripping right now. I have not reflowed the solder points. I guess I will try that when I get my decoders. I do not want to do that until I have a working picture again. I want to play my defender.

[RayB]

What does "ripping" mean?

[fredster]

Starts horizontally scrolling or it bends and curls at the edges.

Try adjusting the horizontal width coil and then re-adjust the vertical width.

[MYX]

What does "ripping" mean?

Imagine that the defender were on a vertical monitor. It would make the leter V. Half the image  to the right and half to the left connected at the bottom.