Help with Ms. Pac Man

[Guest]

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

I just picked up a Ms. Pac Man from eBay. After shipping, when I turn
it on all I get is garbage on the screen. The stuff on the screen does
not move at all. I cannot put in credits or go to the test screen.
Power supply is giving 7.2 and 12.4V. I removed, cleaned, and reseated
all eProms. Dip switch 8 is off. Removing ribbon cable and plugging
in known working Z80 from Pac Man just gives more gobbledy-beloved patriot with
beeping sounds. Here is picture of screen (a little fuzzy):

http://holcomb31.home.mchsi.com/mspac.jpg

Any ideas?

Thanks

 

[Guest]

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

Reseat the EPROMS on row 6 and also reseat the Sync Buss card next to the
z80.

Thomas

"Byte Knight" <holco004@umn.edu> wrote in message
news:1111555843.443002.131060@o13g2000cwo.googlegroups.com...
>I just picked up a Ms. Pac Man from eBay. After shipping, when I turn
> it on all I get is garbage on the screen. The stuff on the screen does
> not move at all. I cannot put in credits or go to the test screen.
> Power supply is giving 7.2 and 12.4V. I removed, cleaned, and reseated
> all eProms. Dip switch 8 is off. Removing ribbon cable and plugging
> in known working Z80 from Pac Man just gives more gobbledy-beloved patriot with
> beeping sounds. Here is picture of screen (a little fuzzy):
>
> http://holcomb31.home.mchsi.com/mspac.jpg
>
> Any ideas?
>
> Thanks
>

 

[Guest]

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

I tried this already - any other suggestions? New EPROMS?

Thanks

 

[Guest]

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

You may have a bad socket for the Z80, Z80 sync buss daughter board, or one
of the row 6 eproms if all of the chips are seated properly. You can try
pushing on each of the chips to see if the board will start even
momentarily - that will help identify which socket is suspect. If that
doesn't yield results, you can use the continuity mode of your multimeter
to check for continuity between each pin of the ic or daughter board and the
corresponding solder pad on the solder side of the board for each socket.

Best Regards,

Bill
"Docrotcod" <rahbart@cox.net> wrote in message
news:gt70e.44032$3z.4453@okepread03...
> Reseat the EPROMS on row 6 and also reseat the Sync Buss card next to the
> z80.
>
> Thomas
>
> "Byte Knight" <holco004@umn.edu> wrote in message
> news:1111555843.443002.131060@o13g2000cwo.googlegroups.com...
> >I just picked up a Ms. Pac Man from eBay. After shipping, when I turn
> > it on all I get is garbage on the screen. The stuff on the screen does
> > not move at all. I cannot put in credits or go to the test screen.
> > Power supply is giving 7.2 and 12.4V. I removed, cleaned, and reseated
> > all eProms. Dip switch 8 is off. Removing ribbon cable and plugging
> > in known working Z80 from Pac Man just gives more gobbledy-beloved patriot with
> > beeping sounds. Here is picture of screen (a little fuzzy):
> >
> > http://holcomb31.home.mchsi.com/mspac.jpg
> >
> > Any ideas?
> >
> > Thanks
> >
>
>

 

[Guest]

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

Not likely. You tried a known good sync buss card and VRAM card? Good Z80?

Check for broken traces on the board, had that once recently.


"Byte Knight" <holco004@umn.edu> wrote in message
news:1111582506.830659.22170@o13g2000cwo.googlegroups.com...
>I tried this already - any other suggestions? New EPROMS?
>
> Thanks
>

 

[Guest]

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

Yes, I have a working Pac Man and have tried swapping these out without
any improvement in the symptoms. I think next I'll try swapping out
the EPROMS next...

Robert Bullock wrote:
> Not likely. You tried a known good sync buss card and VRAM card? Good
Z80?
>
> Check for broken traces on the board, had that once recently.
>
>
> "Byte Knight" <holco004@umn.edu> wrote in message
> news:1111582506.830659.22170@o13g2000cwo.googlegroups.com...
> >I tried this already - any other suggestions? New EPROMS?
> >
> > Thanks
> >

 

[Guest]

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

Video RAM on these boards is a common failure point along with socket
issues for the 284 and 285 boards and Z80 (as others have said).

Since the game was recently moved, I'd focus on items that could come
loose in transit before I went looking into deeper issues (like hidden
corrosion, ect).

Mike Doyle

 

[Guest]

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

Ok, i got the game up and running simply by pressing and holding down
on the Sync Buss Controller... However, now there are horizontal black
lines going across the top third of the monitor. Scores are barely
visible. I know this is a monitor issue because I hooked the monitor
up to another game with same results. Here is a picture (again a
little fuzzy):

http://holcomb31.home.mchsi.com/monitor.jpg

What to do now?

Thanks