RE: Tron regression

From: James R. Twine <jtwine_at_jrtwine.com>
Date: Fri Nov 09 2007 - 09:46:55 EST

   If memory serves, there is some kind of reset signal that is sent out
of the PSU when it fully comes up. Kinda like the "power good" signal
that PC power supplies have. What you are describing sounds like the
kind of screen you get when everything but the CPU is working, so my
guess would be to have a look at that "power good/reset" signal coming
out of the PSU. If you were missing a voltage from the PSU, I would
expect to not have well-formed garbage on the screen.

   In a pinch, you might be able to manually trigger a CPU reset and see
if that wakes things up. I think that there is a little reset switch on
the board stack someplace (if you have not tried that already), or you
can try hitting the reset pin on the CPU itself.

   Also, it has been a while since I had a Tron, but are there some LEDs
on the board that can be used to diagnose here?

   Peace!

-=- James R. Twine, (spam@jrtwine.com)
http://www.jrtwine.com
http://www.deletefxpfiles.com
http://www.checkfavorites.com

> -----Original Message-----
> From: owner-rasterlist@vectorlist.org [mailto:owner-
> rasterlist@vectorlist.org] On Behalf Of EvilJim
> Sent: Thursday, November 08, 2007 4:31 PM
> To: RasterList
> Subject: RASTER: Tron regression
>
> Drat, I seemed to be doing so well.
>
> After burning new ROMs for D2 (for freeplay hack) and D6 (hard
> failures
> in the original ROM), the game came up, both play and freeplay were
> available and I could switch into self-test mode. None of the
> controls
> were working, so tracking that down was the next step.
>
> I think I may have found the culprit, a bad pin on the switch
> return
> line in connector J4. New connectors/pins have been ordered, so
> that
> should be resolved next week. However, in the course of trying to
> track
> down the fault for the CP, I seem to have lost game function and am
> now
> getting a garbage display.
>
> Upon power up, the game no longer works, nor can I get into self-
> test.
> The screen has two halves, left and right, that are both displaying
> nonsense. The left is a repeated pattern, while the right looks
> mostly
> of a solid color with some stray explosion spites tossed around.
>
> Power cycle nor reset switches seem to have any effect on the
> output
> from the boards. Any thoughts on what I messed up, or harmed while
> chasing the harness issue? Does this just sound like something
> else has
> in the logic has failed? Could this be a power issue, something
> too low
> or too high to the boards?
> -------------------------------------------------------------------
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Received on Fri Nov 9 09:47:12 2007

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