Gottlieb System 80b Tilt Switch always closed, game won't boot
William DeLeo
removed everything from the table, cleaned and waxed. While I was in
there I installed a NOS plastic set, cleaned all the posts and changed
over to #47 bulbs. I put the playfield back into the machine and it
booted right up no problem. I got into the test menu and made sure
everything was still working properly, which it was.
Just to make sure the ball feeder was still working, I started a game.
I pressed the left flipper button and instantly the game went into
Tilt. I checked the switches first, and all 3 were clear (plum bob,
ball roll, under PF switch). I have the slam switch disconnected and
permanently closed on the MPU (as per Marvin3m's guide). I
disconnected all connectors from the MPU with the exception of power
and display. On booting, the game instantly says Tilt Switch Closed.
I'm fairly certain the MPU is at fault here, but not exactly sure
where to start checking. Has anyone had this problem, or can they
recommend where to check?
Thanks for any help, anxious to play this again since I rebuilt it!
-Bill
Steve Charland
open.
Steve
System 80, not just a job, it's an adventure
William DeLeo
had been running perfectly.
The Tilt Switch is always closed according to the display.
Gott Lieb?
Hot Shots, and Bone Busters, Inc. I was a little surprised, the first
time I saw it, that 80B's do actually post a message to the display
when the tilt switch is closed.
Jim
Gott Lieb?
would be Z11 for the strobe, and Z14 for the return. Equally, it
could be a bad U4 RIOT, but I would test that last.
Jim
Steve Charland
your game was later. Since your CPU board is saying that it sees the
tilt switch is closed, the A1J5 connection must be good (or you'd see
a 99), unless there is a switch matrix issue. You say there isn't a
tilt switch issue so we'll go from there. If you can coin up, start a
game or go into test, return 7 is working. I don't have the correct
schematic to point you in the right location but on a Bounty Hunter
schematic, the tilts are on strobe 5. Strobe 5 is Z11 on the CPU
board, I'd give that a good look.
Steve
System 80, not just a job, it's an adventure
Steve Charland
Ron Lyons
>
> - Show quoted text -
I worked on a Hot Shots once, and did the mod... took a little bit of
time to do it right, then noticed as soon as I turned it all back on
that it was totally backwards in my game, lol. I plan on one day
doing the mod on a game that actually needs the mod....
Dan Beck
"Gott Lieb?" <r...@papinball.com> wrote in message
news:939cd80d-190d-40d7...@y18g2000yqb.googlegroups.com...
Jim
Rats! I'm out in the garage, working on the English roadster (putting a
rebuilt tach in), and I miss a good System 80 question!
As usual, Jim and Steve are all over it.
Regards,
Dan
Steve Charland
the show and I could answer on time (I still got beat). ;)
-S (CARGPB1)
On Oct 17, 4:18 pm, "Dan Beck" <biscuitbecks@*NOSPAM*cableone.net>
wrote:
Gott Lieb?
actually *finish* a game correctly this year.
Jim
On Oct 17, 7:18 pm, "Dan Beck" <biscuitbecks@*NOSPAM*cableone.net>
wrote:
> Rats! I'm out in the garage, working on the English roadster (putting a
Dan Beck
Heck, my reply was delayed, because I wanted to finish watching PSU
actually *finish* a game correctly this year.
Jim
Sadly, I think my alma mater is done with *finishing a game correctly* for
this year... :-( I went to the University of Wisconsin.
Regards,
Dan
William DeLeo
culprit. I snipped the old one out of the board, installed a socket
and popped a new chip in. First try, the game fired right up!
Now here's the million dollar question, what would cause that 7400N to
blow up? Is it possible its just an old component?
My best guess is I switched over to #47 bulbs from #44's and as a
result the power draw is less. Maybe the change was enough to put that
chip over the edge?
Thanks again!
Bill
GPE
"William DeLeo" <cpsy...@gmail.com> wrote in message
news:9dc6f1d4-08dc-4c3e...@p25g2000yqh.googlegroups.com...
> Man, you guys are the BEST! The first chip I swapped out Z14 was the
> culprit. I snipped the old one out of the board, installed a socket
> and popped a new chip in. First try, the game fired right up!
>
> Now here's the million dollar question, what would cause that 7400N to
> blow up? Is it possible its just an old component?
Accidental short of a switch matrix line to practically anyting else will do
this.
Ed
Gott Lieb?
7, there may have been other return lines blown too. There are two
things I would investigate before turning the game on again. First,
make sure the isolating fish paper between the right flipper's EOS and
the lane change switch is present. A short between the EOS switch and
the switch matrix return line on the lane change switch will be sudden
death for Z14 and / or U4. Secondly, make sure there isn't continuity
between the tungsten contacts on the kicking targets, when closed, and
the point switches on the kicking targets. If there is continuity
between these lines, you will have the same issue as the RH flip as
mentioned above.
No idea why Z14 blew up on you, except as mentioned above. If all is
good, I would have to go with Charland fond name for 74xx IC's -
fuses. :-) Just be grateful U4 didn't get zapped. I would put the
game through switch test, and see if everything is good. Then, exit
the test menu, and put it through switch test again. If everything is
good, chalk it up to being a strained IC chip that was reaching its
life expectancy, (not that they should have one, but it's installed on
a GTB for cripe's sake). ;-)
The cause of failure due to changing the bulbs out is a stretch.
Jim
Dan Beck
"William DeLeo" <cpsy...@gmail.com> wrote in message
news:9dc6f1d4-08dc-4c3e...@p25g2000yqh.googlegroups.com...
Hi Bill,
I have to agree with Jim. Changing bulbs did not contribute to the Z14 chip
dying. As Steve Charland says, switch matrix ICs on System 80 boards are
'fuses' to protect the U4 RIOT. They just die, with no readily apparent
reason.
Regards,
Dan