Re: Bally Motordome (6803) random freeze-ups

John,

If a capacitor is parallel to a set of switch contacts, when the switch
closes, the capacitor is instantaneously and fully discharged. Once the
switch reopens, the capacitor has nothing to "donate" to the duration
of the pulse.

IMHO the cap is there to "debounce" the switch closure. The mechanical
closing of a switch often generates multiple electrical closures due to
dirt and impurities in the contact surfaces. The capacitor resists
these rapid changes creating a smoother single closure.

So by removing the caps, you run the risk of creating multiple events
from a single closure. Probably not the end of the world, but I'm
thoroughly convinced that pin manufacturers would not add parts and
labor into a game if it wasn't warranted.

AL
www.PinMonkeys.com


John wrote:
No, I haven't replaced them yet. I will when I get a supply of them on
hand. Any idea where I can get some cheaply?

Just so I understand what a capacitor does on a switch. It holds a contact
charge a little longer than the duration of the contact so that the MPU can
recognize it. With the capacitor snipped, the circuit is closed only for
the duration of contact and sometimes MPU will miss it (this is what I see
on my 4 switches with the caps snipped).

Is that correct?

Thanks,
John

"AL" <AL@xxxxxxxxxxxxxx> wrote in message
news:1157397161.135860.319030@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
John,

Did you replace the capacitors you removed? If not, you're in for
more random resets in conjuction with solenoid activity. Also, if the
connectors seem tight, just plugging and unplugging a few times will
assist in cleaning.

AL
www.PinMonkeys.com


John wrote:
I think I have solved the problem (somewhat). I took out the circular
bulb
as was distracting me whicle working on the machine. When removed, I
couldn't get past "flash 7" on the controller board. Put the bulb back
and
the game would flash all the way up to 9 and boot, but still exhibit
flaky
behavior. I figured this must be a power/voltage issue. First I removed
my
extension cord from the mix and plugged directly into the wall. No
change.
Secondly, I reseated the connector going from the power board to the
controller on both ends and that seems to have fixed the problem.

Now I doubt that will permantently fix the problem, so what should I do
next? Clean/scrape the connector contacts? Reflow solder on power board
and
controller? (I am not qualified to replace the headers)

Thanks,
John


.

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