Re: Friday Vector Trivia #001-006

  Hi Darren...

Yep, bad description on my part. It was running good under the hood,
just deaf and blind.

jess

On 10/25/2010 8:00 AM, Darren Finck wrote:
> Thanks for the follow-up. I particularly enjoy reading about the
> diagnosis and repair of PCB problems. Helps me understand common
> issues, as well as hone troubleshooting skills.
>
> On PCB #2... I assume it wasn't "fully" dead, as all the logic should
> have worked fine with +5V. However, the jacked +/-22 (and +12, and
> +/-15...) would have left it unable to generate and amplify audio or
> video output... so the only way you would have been able to tell it's
> "running" would have been by probing address/data lines. Perhaps an
> unimportant distinction between "dead" and "vegatative state" (playing
> blind & deaf...)
>
> Thanks again,
> Darren
>
> --- On *Sun, 10/24/10, Jess Askey /<jess@askey.org>/* wrote:
>
>
> From: Jess Askey <jess@askey.org>
> Subject: VECTOR: Friday Vector Trivia #001-006
> To: vectorlist@vectorlist.org
> Date: Sunday, October 24, 2010, 11:54 PM
>
> Heheh... well, finally following up on this one... I didn't have
> email for like 3 weeks after I posted this so I went through and
> fixed all my Asteroids PCB's in one fell swoop. Here is a rundown
> of each of them with the symptoms and solutions.
>
> PCB #1:
>
> Plays, had screen distortions as described in this thread where
> there were flat spots where the beam seemed to fold back on itself
> in a repeating fashion across the screen. As everyone guessed, it
> was the DAC. I ordered a few from Mark C and in the interim
> snagged one from a spare Omega Race cabinet just to test. Added a
> socket and threw in the replacement DAC and all was good to go.
>
> PCB #2
>
> Dead, smelled hot somewhere. After investigation the filter caps
> on the +/- 22V supplies had spewed their guts at some point a long
> time ago in a galaxy far away (oh, sorry , wrong game). They were
> indeed warm too. I replaced them expecting another issue but all
> was good. I made sure the regulators were okay on the +/- 15V
> rails and they were running cool. I can only assume that something
> happened on the AR that this PCB was installed with at some point
> (direct AC to the caps maybe).
>
> PCB #3
>
> Dead, no clock on CPU. Investigated crystal, broken. Replaced,
> good to go.
>
> PCB #4
>
> Played had screen distortions similar to PCB #1 but they were less
> often (higher bit). Snagged the other DAC from spare Omega Race
> PCB and fixed everything right up. Good to go.
>
> PCB #5
>
> No screen. Had some random beeps. Put into self test, had screen
> and ROM letters. Dug through my pile of manuals trying to find the
> correct REV manual to match the REV on the PCB and finally found
> one. Looks like it was a bad ROM at F1 (Self test showed 2). PCB
> was a Rev F. The ROM at F1 was oddly not a mask ROM, looked okay.
> Pulled it to verify and saw a pin bent under. Straightened. Viola.
> All good.
>
> PCB #6
>
> Dead, no clock on CPU. Investigated crystal, broken. Replaced,
> good to go.
>
> It ended up that I only had 6 Asteroid PCB's and not 10. The
> others ended up being Asteroids Deluxe PCBs and a Lunar Lander
> PCB. Once I get a bench setup again (just moved). I will start
> going through those bad boys.
>
> I almost shit going through my PCB's when I saw a big fat 68000 on
> one of them... but it was just a Food Fight!! :-) Solace for Quantum.
>
> Overall, pretty boring problems on all of these, but Im not going
> to complain.
>
> jess
>
> PS - does anyone have a few of those grey plastic rails that Atari
> used for PCB brackets? I have a cabinet that is missing all of
> them and I want to put it back together. I need two long ones and
> two short ones (game PCB and ARII). Email off list if you have
> some spares. I just found a stash of Atari LED switches that I
> would trade if interested. Otherwise, let me know if you are
> looking for something specific.
>
>
> Jess M. Askey
> *ASCII Solutions - Software Design and I.T. Services*
> 3315 Buntwing Ln
> Fort Collins, CO 80524
> 307-760-5270
> http://www.ascii-solutions.com <http://www.ascii-solutions.com>
>
>
> On 9/13/2010 11:49 AM, Fabrice GIRARDOT wrote:
>> Andrew Welburn wrote:
>>
>>> don't forget 7474 !
>>
>> I agree at 100% ! :-)
>>
>> Regards,
>> Fab
>> ---------------------------------------------------------------------------
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>
>

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Received on Tue Oct 26 23:56:46 2010