Re: Omega Race Question

OK - I may still need some more help on this lousy board. >:|

1) I fixed the logic part - so the game actually plays

2) I fixed the sound

3) I'm getting a full Y output on my *scope* but I can't figure out why
the left (X half) of the screen is missing. The TL08x op amps on the x
side are getting proper voltages and the inputs and outputs look like
they've got a good signal. As I go further back into the circuit I'm not
seeing anything that stands out as a bad signals. Is there anything I
should be suspicious of when the left have is missing?

The other thing is - I've actually hooked this board up to a working G05
monitor and the output looks just like on the scope - meaning, all the
retrace lines are there, but I can see that the correct shapes are in
there. I'm actually amazed the watchdog circuit allowed such bad signals
through.

So... 2 questions

1) I've traced back as far as the DAC. Do I need to go further? Or
should I suspect the DAC? It's an AD561J

2) Should I suspect the Z blanking circuit?

Hopefully I made some sense.....

Thanks!!!

Matt

> _____________________________________________________________________
>
> On Thu, 2 Sep 1999, John Robertson wrote:
>
> > Typically the checksums in KK are generated with a NOP fixture for the CPU,
> > then you start/stop the read on the chip select.
> >
> > As for the suspect TL08X, if you get no output, but you get input, have you
> > checked the supply voltage for these devices? Have you scoped the inputs?
> > It would be unlikely that both have failed unless the supply for them went
> > ballistic and blew them together...
> >
> > John :-#)#
> >
> > At 04:18 PM 9/2/1999 -0700, you wrote:
> > >I recently fixed an Omega Race board so that all the logic now works. The
> > >game passes all the ram and rom tests and coins up. I think that I just
> > >need to replace one or more of the TL08xCP Op Amps because I'm not getting
> > >any X or Y signal. The X and Y pots are fine.
> > >
> > >Anyway - maybe someone could answer this question for me. I fixed this
> > >game using my KK Test fixture. The instructions also include signatures
> > >for certain roms but don't really explain the setup for getting the
> > >signatures. Does anyone know how to do this? I'm just curious since it
> > >might help me in the future.
> > >
> > >
> > >Matt
> >
> >
> > John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> > Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> > http://www.flippers.com
> > "Old pinballers never die, they just flip out."
> >
> >
>
>
>
Received on Sat Sep 11 02:03:30 1999