Re: RE: Techtoolslist Digest, Vol 4, Issue 7

Maybe the Z80 pod may also have some kind of similar
issue as well?

Tony

--- John Robertson <jrr@flippers.com> wrote:

> It's starting to look like a design flaw. The
> 68B21's RESET line is
> simply tied to Vcc through a pull-up resistor. I've
> now jumpered that
> to the board RESET line and I get a clean start up
> almost every time
> (I have substituted a good 68B21 to no avail
> previously).
>
> Sooo, if this works in the game, another Tech Tip
> will appear on RGP I guess.
>
> John :-#)#
>
> At 11:51 AM -0600 2/23/05, Robert C. Bullock wrote:
> >John:
> >
> >-----
> >However when I replaced the suspect 175, no sounds,
> and when I put the
> >original 175 back in the (now socketed) PCB, I
> don't get the sounds even
> >with the Bugtrap the same way.
> >-----
> >
> >Hmm, the only similar thing I've seen is a bad -5V
> reg (7905) on Atari
> >Roadblasters in the sound section. Putting my logic
> comparator on one of the
> >chips fixed a problem with the scrolling playfield,
> but killed the sound.
> >Take it off, it scrolls again, sound works.
> >
> >Replacing the voltage regulator fixed it. The
> voltage on the pulse to sync
> >that section of the board was low.
> >
> >You'll have to Google this or give me a deal on
> that pinout cart :) and I'll
> >dig the particulars back out. This sounds somewhat
> similar.
> >
> >
> >_______________________________________________
> >Techtoolslist mailing list
> >Techtoolslist@flippers.com
>
>http://seven.pairlist.net/mailman/listinfo/techtoolslist
>
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC,
> Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes,
> VideoGames)
> www.flippers.com
> "Old pinballers never die, they just flip out"
> _______________________________________________
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>
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>

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Received on Wed Feb 23 12:02:29 2005