Re: TECH: Major Havoc

 Well, following Joe B's advice, I bypassed the X & Y OUT signals by pulling
the connections from my Tempest harness and jumped them to the X/Y OUT pads
on the main PCB. The board is still not working although the pattern on the
screen changes a slightly but it's still a bunch of scrambled jumbo that
reminds me of an EKG. :)

 I've reached the limit that I am willing to tinker with the PCB - who
repairs these that can do so in a timely manner?

 Thx.

-Steve P.

----- Original Message -----
From: "Joe" <joe@joesarcade.com>
To: <vectorlist@vectorlist.org>
Sent: Tuesday, January 04, 2005 3:52 PM
Subject: RE: VECTOR: TECH: Major Havoc

Yep, no can do.. Maybe Clay was just mistaken or looking for more repairs :)

You can still use your scope on the test points on the board to see the
image... Or, pull the X and Y signals from the harness and alligator clip
them to the points on the boards. You will get an image.

IMHO for your problem, I would most likely start tracing your X and Y back
to the outputs from the dac with a scope (actually first opamps.) I think
you may find that you have a bad DAC or something broken on the digital
side. Tough to say though.. First use your scope.

A certain Space Duel board comes to mind that had a similar problem and I
believe I found a bad DAC in combination with a LF13201. IIRC of course,
that was years ago.

JB

________________________________

From: owner-vectorlist@vectorlist.org on behalf of Steve P.
Sent: Tue 1/4/2005 12:13 PM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: TECH: Major Havoc

Thanks for the reply. I thought that it sounded odd plugging MH into SD w/o
an adapter, thus the post. :)

-Steve P.

----- Original Message -----
From: "Tom McClintock" <tomm@mgcap.com>
To: <vectorlist@vectorlist.org>
Sent: Tuesday, January 04, 2005 12:55 PM
Subject: Re: VECTOR: TECH: Major Havoc

>
>
> Steve P. wrote:
>>
>> Is it possible that the Tempest adapter card might have a bad chip? I
>> know it controls the pincoushining, but is there more to it than that?
>
> The adapter PCBs only do two things as you have noted - remap the pinouts
> and provide pincoushion correction.
>
>
>
>> Also, can I plug the MH PCB into a Space Duel harness w/o the adapter
>> card as a way of testing? I searched Dejanews and Clay Cowgill mentions
>> that you can plug the MH into a SD harness with no ill effect.
>
> Uh, you can take a quick look a thte pinouts for each and see that the
> video outputs on Major Havoc are quite different than either Space Duel or
> Gravitar. So, I would say no to this question.
>
> Here are some details on the conversion PCBs that I cobbeled together
> earlier this year:
> http://www.ionpool.net/arcade/mh/major_havoc_conversion.txt
>
>
>
> tm
>
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Received on Wed Jan 5 01:23:28 2005