Tech: Q*Bert knocker

Archived from groups: rec.games.video.arcade.collecting (More info?)

Chuk wrote:
> Having an issue with my Q*Bert knocker. It is intermittent. There is no
> real pattern. Some times it knocks, other times it doesn't (mostly doesn't
> knock). I've tried 2 different power supplies and both have the same
> results. Flakey solenoid?

Yes, high probability that the knocker is bad.

You can buy replacements for not too much, I forget where, what the pin cross
ref is, and how much -- but they are out there.

Archived from groups: rec.games.video.arcade.collecting (More info?)

prOk wrote:
> have you reflowed the RFI board? That's a common source of intermittent
> behavior

Does the knocker go through the filter board? If so, good point, those filter
boards have a tendency to fry.

>
> /b
>
> http://www.tutankham.com
>
> "Chuk" <chuk@ourcade.com> wrote in message
> news:39mtcfF63n1g0U1@individual.net...
>
>>Having an issue with my Q*Bert knocker. It is intermittent. There is no
>>real pattern. Some times it knocks, other times it doesn't (mostly
>>doesn't knock). I've tried 2 different power supplies and both have the
>>same results. Flakey solenoid?
>>
>
>
>

Archived from groups: rec.games.video.arcade.collecting (More info?)

Glenn wrote:
> > Yes, high probability that the knocker is bad.
> >
>
>
> I've never realy seen a bad set of knockers
>
> ( . )( . ) OO VV
>
> They're all good!

John,
Look at the schematics for Qbert. There is a transistor that controls
the knocker on the main cpu board. Check to see if there are dry solder
joints. I forget which one it is, but it's next to a few of the
transistors which look like Tip102's. Check to see which one controls
the knocker, there may be dry solder joints around it and you're
getting intermittent connection. Secondly, check to see which connector
is responsible for the knocker. Could be a tarnished pin. Change the
connector out.

John