G

Guest

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

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?
 
G

Guest

Guest
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.
 

Prok

Distinguished
Oct 1, 2003
159
0
18,680
Archived from groups: rec.games.video.arcade.collecting (More info?)

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

/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?
>
 
G

Guest

Guest
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?
>>
>
>
>
 
G

Guest

Guest
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
 

Glenn

Distinguished
Mar 16, 2003
177
0
18,680
Archived from groups: rec.games.video.arcade.collecting (More info?)

> Yes, high probability that the knocker is bad.
>


I've never realy seen a bad set of knockers :)

( . )( . ) OO VV

They're all good!
 
G

Guest

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

coming from the pinball side of things - things that can be bad with
knocker assemblies:

nylon tip on the plunger broke off (so the knocker is still firing, but
the plunger is much shorter, the pulse is shorter so doesn't pull in
far enough.)
Tiny wires on the coil that go to the terminals bad joint
If there is a diode on the coil, replace it. (It's there to prevent
collapse voltage spikes from damaging upstream components)

In all probability your coil itself is OK, it's just a coil of wire.
Most likely it's something else either above or what others have said
about the other video boards