TECH: Millipede and Centipede boards

[Guest]

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

All,

I need your guys thoughts here. I have a millipede machine that the
trackball motions will not move down. I have tested a working
millipede board in this cab and it works fine so I know that it is a
pcb issue. I have changed the 74ls191, 74ls157, and the 4584 and still
this happens. Any ideas? And believe it or not I have a centipede
board with the same issue. Now I do not what to change out the chips
on the centiped like I did on the millipede just to find out the same
thing. Also, I have piggy backed chips of the trackball circuit on the
centipede with no change. I am about ready to trash these both. I
have been working on them for awhile and I would like to get these fix.
Please let me know. Thanks in advance.

 

[Guest]

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

I had a Centipede like that once and it was a bad connection to the
trackball. Try unplugging and reconnecting the harness at the trackball and
at the control panel harness plug.

Mark Hooks

"Plisskin" <scorpiokings@yahoo.com> wrote in message
news:1126423078.723576.58020@g44g2000cwa.googlegroups.com...
> All,
>
> I need your guys thoughts here. I have a millipede machine that the
> trackball motions will not move down. I have tested a working
> millipede board in this cab and it works fine so I know that it is a
> pcb issue. I have changed the 74ls191, 74ls157, and the 4584 and still
> this happens. Any ideas? And believe it or not I have a centipede
> board with the same issue. Now I do not what to change out the chips
> on the centiped like I did on the millipede just to find out the same
> thing. Also, I have piggy backed chips of the trackball circuit on the
> centipede with no change. I am about ready to trash these both. I
> have been working on them for awhile and I would like to get these fix.
> Please let me know. Thanks in advance.
>

 

[Guest]

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

I don't have the centi schematics in front of me, but a missile command
that i did the other week with the same problem had another 4000 series
chip in there somewhere and it turned out to be that...

I think.

The liberator also had a track ball problem, maybe it was that one )
I forget now! And i haven't been keeping logs lately either - doh!

I have centi with the same problem just brought round tonight. Need to
make a jamma loom up for it first before I can work on it though so it
may be a week or two since I hate making looms.

 

[Guest]

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

>Also, I have piggy backed chips of the trackball circuit on the
> centipede with no change.

Piggybacking will not always tell you if you've got a bad part
or not. It depends on the failure mode of the IC you are trying
to test.

Alex
----
ayeckley@elektronforge.com
www.elektronforge.com