Re: Tron regression

James R. Twine wrote:
> 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.
>
It sounds like you are referring to the Reset loop problem aka "Cut the
purple wire". Once the connectors are all taken care of, I will be
looking into supply voltages again, esp this reset line output. I will
dig around and see if I can get an answer, but does anyone recall how
close to nominal these voltages need to be?

IOW, the main supplied voltages are +5 and +12 volts, but what kind of
leeway do I have as a range around those values?

The original reset buttons (3: 2 on board and 1 on the coin door service
panel) are having no effect when used. Even powering down and back up
is doing nothing. Hence my concern that I messed something up.
Although, given the age, it's possible another part has just given out.

> 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?
>
There is one yellow LED on the stack, not sure of its function, I will
look into that as well. I have noticed it sometimes on, sometimes off,
but only in passing, not in connection with anything I was doing
specifically.

>> -----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 12:28:04 2007