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Main => Monitor/Video Forum => Topic started by: maddags on January 07, 2009, 06:12:23 pm

Title: scrambled picture on k7500
Post by: maddags on January 07, 2009, 06:12:23 pm

 :hissy:

   I have working wgk7500 med resolution monitor and using Avga2 card on my computer running xp.

  I have installed the avga drivers and used the snyc utility that Andy told me to do and everything works great.
  Now when I go to hook up the VGA breakout cable, i notice on the connector from the jamma board that on the monitor board that the hsync and vsync are not present(no wires coming off the pins) it just has the one wire coming off the Horizontal comp sync pin. So i removed the pin connector from the board and hooked up the VGA breakout cable which has the hsync and vsync at pins one ant two and Red(pin10), Green (pin 9), blue (pin 8) and ground at pin 7.  When i started the computer i get nothing but scrambled video (pictures attached). I have the output set to 512*384 32 bit.
 
 I have tried to adjust the vertical and horizontal sync from the control PCB and still The same problem.

Any help would be greatfully appreciated.

Title: Re: scrambled picture on k7500
Post by: grantspain on January 07, 2009, 07:05:26 pm

something to do with your sync wiring

Title: Re: scrambled picture on k7500
Post by: Kevin Mullins on January 07, 2009, 07:15:26 pm

Just curious as to why you changed the sync wiring if it was working already?
Was it working on that monitor or a pc monitor?

It is typical for an arcade monitor to only have negative composite horizontal sync connected. Which is probably what the ArcadeVGA is trying to output to it.

Title: Re: scrambled picture on k7500
Post by: maddags on January 07, 2009, 07:31:28 pm

I wiring setup was from the original pcb from golden tee cabinet, that i had purchased a while back and now want to change it a mame cabinet.
The monitor worked great with the golden tee pcb board.

I tested the AVGA card setup on my computer monitor conected to the dvi port on the card and set the resolution to 512*384 as per andy. 

The problem is that when i looked at the pin out wiring from the main board i noticed that the only sync beng used was the horizantal/ comp sync located at pin 5. So when i removed that pin connector and added the breakout vga cable pin connector it has two syncs set at pins 1, and 2 ( horz/ comp sync and Vertical sync).  Would this be the problem.

Could i just tie the two sync cables from the vga cable toghether and connect to pin 5 (horizantal/ comp sync pin)?

Title: Re: scrambled picture on k7500
Post by: maddags on January 08, 2009, 03:00:14 pm

Would anybody know? I hate to bump this.

Title: Re: scrambled picture on k7500
Post by: Kevin Mullins on January 08, 2009, 05:17:10 pm

Quote from: maddags on January 07, 2009, 07:31:28 pm

Could i just tie the two sync cables from the vga cable toghether and connect to pin 5 (horizantal/ comp sync pin)?

Try it..... just take a piece of wire and jump from one pin to the other on the monitor connector.

There's also a horizontal hold potentiometer towards the front of the main chassis you may try adjusting. ( VR701 )

Title: Re: scrambled picture on k7500
Post by: maddags on January 08, 2009, 07:31:49 pm

Thank you, I'll give a try when i get home and will post the results.