Re: Gottlieb System 1 (before you /sigh please?)

Have you tried running it with the PROM adapter board out of the game
yet? One other thing, and I am just tossing this out there, but try
removing all of the dip switches if they're socketed. I have made it a
practice to replace all of the dips on a Sys1 CPU, because I have had
unexplainable erractic things happen on too many occasions with the old
ones in place.

As far as the 7405 goes, if you're referring to Z9, all pins should be
high or low after starting a game once the ball is served into the
shooter lane. In attract mode, pins 8, 9, 12, and 13 of Z9 pulse,
while the others are high or low. If you are talking about the Z28
7405, the pins are either high, low, or not used.

BTW, the Pascal board thing was a joke.

Jim


Matty-t wrote:
Jim,

My logic was running along the lines of 'hey, I got these two CPU
PCBS, I'm gonna make a good modified one, and if it's all workin ok, I
just saved some bucks and everything is still OEM (for the most part)'

See, when I got the machine the CPU PCB was gone. The op that sold it
to me gave me two spares. One with corossion damage (very minor) but
complete, and the other that looked immaculate but was missing the
switch spider. So I transplanted the two matching spiders from the
corrosion PCB to the clean one, and modded everything up.

Now for personal edification, I am a noob to these parts, but not a
noob with technology. So I am very confident in my abilities to
diagnose, repair, solder, etc, etc. SO I would like to rule out my
shunt work and transplant work. However I will take the advise one step
and retest my shunts as the probability of a defective part is always
an remote possibility.

I will also re-ring my adapter card against the documentation, and
re-verify the code of the 2716. The Intel ROM is brand new, and my
programming equiptment has been 100% solid from day one. There is an
off chance that the image is bad I agree. I got it from clay's site.
Anyone else use the code posted there with success?

I did unplug just J7 once, as the other is needed for the start button
;) As I stated before it basicly counts smaller incriments at that
point, and there are coresponding sounds with it. Plug J7 back in, and
I get *more* sounds and *more* scoring. With or without the harness
connected, I get good strobes on all pins of the 7404 wich suggests a
good spider and 7404 as per a doc I read on another site. BUT the
coresponding 7405 just has every other pin steady hi/low/hi/low
respectivly. The doc mentions these should be pulsing, but tells me
nothing of what to do otherwise. It just kinds dead ends there. Sucks
that the manuals are not online :(

I did however socket and replace all three buffers on that corner of
the PCB for future troubleshooting issues. I like minimal downtime :)
There was incidently no change in condition upon doing so.

I have not repin'd any connectors as of yet. But upon inspection
everything looks very nice, clean, and all voltages all over are solid.
Very minimal ripple anywhere. I do have plans to ohm out the
connections. But thats a lot to do at once, and I was going to do it
tomorrow.

I appreciate all the help guys. Don't give up on me.

- Matt

Gott Lieb? wrote:
Get one of Pascal's boards (j/k). You knew someone had to say it.
:-)

I would first try to isolate the problem to either the CPU board or the
PF. Disconnect A1-J7 before you turn the game on. This will isolate
the playfield from the switch matrix . Now turn the game on, start a
game, and see if the points are still racking up. If so, it's your
CPU. If not the problem is either in the wiring to the PF or the PF
switches. Since you stated that it's scoring "single points", my hunch
is that the CPU is flaking out somewhere.

If it's the CPU, double check your shunting diode work, and possibly
your PROM adapter. Another thing is maybe the PROM code is corrupt.
Try reburning a 2716, if you already haven't.

Two more questions, have the connectors been repinned, and are you
using the stock CPU / driver board harness?

Jim


Matty-t wrote:
<snip>

I will also add that I seem to have no CPU controlled solenoids, But
couldn't this be due to the switch matrix taking over the buss
constantly? The only other switch that seems to register while this is
going on is the 'tilt' and it *does* work.

Revised CPU w/input shunting diodes on switch matrix

Made adapter card and am now using a 2716 in place of PROM
performed ground mods!

.