Re: Question about blackened edge connectors...

From: Kurt Mahan <kmahan_at_xmission.com>
Date: Thu Aug 23 2001 - 01:58:09 EDT

Don't forget the other fun feature -- the contacts burn and all the current
flows through the sense lines. And then the sense resistor on the the
AR board burns up. Annoying.

Kurt

> This is common on most/all Atari PCBs that use the edge connector. Usually,
> the problem is that over time you get a little oxidation on either the
> ground pad or one of the 5/12v supply tabs. Not enough to cause an open,
> but enough to increase the resistance. As a consequence, the voltage drops.
> The AR PS senses this, and then boosts the voltage to compensate. Over
> time, this will heat up and oxidize more, resistance increases, PS
> compensates, repeat.. Sometimes the end result are pads that are completely
> burnt up or the harness starts to melt.
>
> To fix, you either need to repair or replace the damaged pad(s). You should
> burnish them clean as opposed to sand -- sanding can remove too much of the
> pad as well as scratch which leads to oxidation again. You also need to
> inspect the connector and make sure that it clean. Note that the contacts
> will lose tension over time and as they get hot -- it may be time to replace
> the connector altogether.
>
> With this type of problem, the sooner you fix it the less likely it is to
> create a bigger problem.
>
> Good luck, and have fun.
>
> BTW: Did you grow up in Colorado?
>
> > -----Original Message-----
> > From: owner-vectorlist@synthcom.com
> > [mailto:owner-vectorlist@synthcom.com]On Behalf Of Andrew Wilson
> > Sent: Wednesday, August 22, 2001 7:13 PM
> > To: vectorlist@synthcom.com
> > Subject: VECTOR: Question about blackened edge connectors...
> >
> >
> > My Asteroids Deluxe has been having trouble with its edge
> > connector since I
> > bought it. Occasionally it will fail to boot up, at which point I open up
> > the machine and wiggle the edge connector, then power up the
> > machine and it
> > seems to solve the problem. I'd always assumed that maybe there was some
> > oxidation building up on the tabs which needed to be scraped off
> > by wiggling
> > the edge connector, but I didn't worry about it much because I knew the
> > "fix" and it didn't happen very often.
> >
> > Well, it happened again, and this time wiggling the edge connector didn't
> > work. This time I ended up taking the board out and took a good
> > look at it,
> > and the topmost tab on the PCB board (the one that connects to GND, I
> > think - I didn't have my meter or my pinouts handy) was blackened, and had
> > peeled off the PCB a little bit. I took a little sandpaper and cleaned off
> > the black stuff, and the game works again, but now I'm concerned that
> > there's a more serious problem that I should try to solve instead of just
> > ignoring it.
> >
> > I dimly recall that someone else had a problem like this a few months ago
> > with their Asteroids, but I can't seem to find it in the
> > archives. Is this a
> > common problem with these PCBs? The game seems to work fine otherwise, but
> > if someone can suggest a solution, I'd be much obliged.
> >
> > Thanks,
> >
> > Drew
> >
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Received on Wed Aug 22 22:57:15 2001

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