dreamcast to arcade monitor picture is halved...

[tenex2mg]

Greets All,
     I'm not sure if I'm posting in the correct forum but I'll give it a go here.  I managed to power up my arcade monitor (old WG 25k7194) but am running into a new snag adding in my trusty dreamcast.
     I've hacked the vga-box (following directions found elswhere on this site) which basically entailed grounding out pin 6 in the vgabox thus letting it display at 15khz.  It was working perfectly for a few days, but then the image started getting split in half...in other words the image would start in the middle of the screen and carry over to the other side.  If I try to adjust my "h-position knob" i loose the picture totally.  Its important to note that I have no such issues when attatched to computer via vgacard.

any thoughts?

thanks in advance

-jeff-

[Dave_K.]

Greets All,
     I'm not sure if I'm posting in the correct forum but I'll give it a go here.  I managed to power up my arcade monitor (old WG 25k7194) but am running into a new snag adding in my trusty dreamcast.
     I've hacked the vga-box (following directions found elswhere on this site) which basically entailed grounding out pin 6 in the vgabox thus letting it display at 15khz.  It was working perfectly for a few days, but then the image started getting split in half...in other words the image would start in the middle of the screen and carry over to the other side.  If I try to adjust my "h-position knob" i loose the picture totally.  Its important to note that I have no such issues when attatched to computer via vgacard.

any thoughts?

thanks in advance

-jeff-

I guess you ment to say cut pin 6 right?  The instructions are to remove the ground from pin 6 but leave pin 7 grounded.  Well if it was working for a couple days I'll assume the hack was correct.  About the only other thing I can think of is possible one of the h/v pins not making contact in the connector or coming loose in the PCB.   Look at the vga box's plug and make sure all the pins are at the same length (sometimes then can get pushed in).

[tenex2mg]

Well the funny thing is that if i hook up the same vgabox to my computer monitor...it displays perfectly.  Go fig?  Anyways, I picked up another vgabox off of ebay..should be getting it in a few days...I really can't wait to play houe of the dead 2 on my arcade monitor...

[SNAAAKE]

EDIT:

I opened my dreamcast and cut the 31khz on the dc motherboard itself.I just took my soldering iron and burned the very thin line/trace/whatever its called.

Also,never understood the pinout thing from gamesx  
(just so you know)

[Dave_K.]

Well the funny thing is that if i hook up the same vgabox to my computer monitor...it displays perfectly.  Go fig?  Anyways, I picked up another vgabox off of ebay..should be getting it in a few days...I really can't wait to play houe of the dead 2 on my arcade monitor...

If your VGA box works on your computer monitor then its outputting 31khz and not 15khz (in other words you did not hack it corretly for arcade monitors).

[tenex2mg]

Thanks for the replies, well I guess I did a temporary hack because it was working perfectly for a couple of days (on the arcade monitor), it sorta petered out when I hooked up the audio..where could I get a pic of the inside of the dreamcast so's I could follow snaaake's advice and disable the 31khz output.

as always thanks,

-jeff-

[Dave_K.]

I don't know why snake would want to do something like disable the 31khz inside the DC motherboard!?  Unless he ment inside the VGA box.  There is absolutely no reason to do this inside the DC itself!  Just cut a single wire inside your VGA box and thats it...no solder, nothing else...just put the screws back in and you are done.

I guess the only had part is cutting the correct wire #7 (trace it from the dc connctor into the vga-box's pcb.  If you cut the wrong one, then just twist/splice it back together.  

[SNAAAKE]

I don't know why snake would want to do something like disable the 31khz inside the DC motherboard!?  Unless he ment inside the VGA box.  There is absolutely no reason to do this inside the DC itself!  Just cut a single wire inside your VGA box and thats it...no solder, nothing else...just put the screws back in and you are done.

I guess the only had part is cutting the correct wire #7 (trace it from the dc connctor into the vga-box's pcb.  If you cut the wrong one, then just twist/splice it back together.  

I never found the wire on the vga box itself
I am too impatient and I have 2 DCs so whatever but thats just me.