Re: Tempest problem.

I just wish the other tempest board I'm working on was as forgiving.

It won't boot, something isn't right with the Vram, and Vrom addressing.
Using the fluke I can read all the roms and check the normal game ram just
fine. But can't read the vroms or do a mem check on the vram. The buffers
appear to toggle just fine when trying to access with the fluke, (in normal
game run they don't toggle at all) I went ahead and replaced them still no
joy.

It's a rev 2 board it looks like, and the w4, and w2 jumpers aren't present.
So I'm still kinda at a loss.

When I put it in test mode, I get one short low tone and nothing. Still
probing around trying to figure out where the problem is..

Kevin

On Tue, Nov 17, 2009 at 7:48 AM, Andrew Welburn <andy@andysarcade.net>wrote:

> heh, those kinds of faults where you can kickstart a stuck node are very
> rare, i've done maybe 3 of them in 10 years, and only one of them later
> failed... one was on an asteroids, one was on a battlezone, and the other
> was on a more modern game i forget what it was, but it was that one i had to
> revisit and replace the offending IC.
>
> So i'd say you have a 33% chance of it re-appearing, but at least yuou know
> exactly where to look if it does re-appear.
>
> Andrew Welburn
> www.andys-arcade.com
>
> ----- Original Message -----
> *From:* Kevin Moore <talon.k@gmail.com>
> *To:* vectorlist@vectorlist.org
> *Sent:* Tuesday, November 17, 2009 1:37 PM
> *Subject:* Re: VECTOR: Tempest problem.
>
> Yeah, I just hit it with +5v and it started toggling. The problem hasn't
> come back even through power cycles. It's been running just fine for the
> past 12+ hours. Which seems odd to me, so I'm going to keep an eye on it for
> a while longer.
>
> Kevin
>
>
> On Tue, Nov 17, 2009 at 7:27 AM, <kstillinger@sc.rr.com> wrote:
>
>> Hey Kevin-
>>
>> What exactly do you mean when you say you 'toggled' the pin?
>> Did you force it high with a momentary short to 5V? If so, did it start
>> making the appropriate transitions afterwards? Does the problem re-appear
>> after power cycling?
>>
>> Just curious and looking for more info.
>>
>> Kerry
>>
>> ---- Kevin Moore <talon.k@gmail.com> wrote:
>> > Thanks Andrew. I have the alt circuit with the MC3410. Pin 4 was stuck
>> low.
>> > Toggled it, and the problem went away. I'm sure the problem will come
>> back,
>> > When it does, I'll have to check the proceeding circuit to see if the
>> > problem is with the 3410, or somewhere before. But at least I know where
>> the
>> > problem lies.
>> >
>> > Thanks very much for pointing me in the right direction.
>> >
>> > Kevin
>> >
>>
>>
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>>
>
>

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Received on Tue Nov 17 08:55:45 2009