Re: Re[2]: TECH: Tempest +5v line

On Sun, 2004-06-06 at 21:48, =?koi8-r?Q?=22?=peter
jones=?koi8-r?Q?=22=20?= wrote:
> -----Original Message-----
> From: "James Bright" <james@quarterarcade.com>
> To: <vectorlist@vectorlist.org>
> Date: Sun, 6 Jun 2004 19:48:04 -0400
> Subject: RE: VECTOR: TECH: Tempest +5v line
>
> >
> >
> > It is what is it. "Atari's Audio Regulator II board uses +SENSE and
> > -SENSE to help regulate voltage on the power supply. Unfortunately, bad
> > connections can sometimes cause invalid return values and affect voltage
> > reading."
> >
> > Bad connections at the edge connections, or connectors that get dirty
> > over time, cause increased resistance. The ARII board tries to
> > compensate (using the + and - SENSE lines) and supplies more voltage.
> > This can lead to burn out of R29 (I've actually witnessed this happen in
> > a game that was working moments before). I am sure I've seen a more
> > detailed explanation before, but I just wrote down what I needed for my
> > notes. Simply removing this feedback helps prevent the burnt edge
> > connector. At worst, you might (eventually) have a lower +5V line. But
> > what you're really doing is avoiding burning up R29 and the melting the
> > edge connector.
> >
> > JB
> >
>
> unless your very unlucky,
>
> the 5v and ground signals use multiple contacts, the feedback doesnt.
> if you get bad connections on the feedback the voltage will rise way above 5v.
>

I think this problem is what killed one or two AVG chips on my Space
Duel.... or at least that is what I suspect did it. (Or course, why
does it always have to kill the part that is 'no longer available' ?).

-- Curt

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Received on Mon Jun 7 10:00:19 2004