Tech: I built me a playfield tester

[beaver]

While the clear on my playfield is drying, I decided to build me a
playfield tester. It allows me to test every switch, light, solenoid
and associated circuitry safely without risking my CPU board and from
the comfort of my work bench.

http://www.edcheung.com/album/album05/pinball/playfield3.htm#tester

If I get complaints about the size of the page, I will move it to a new
one.

Edward Cheung

[David Schulpius]

Holy crap! Cool! Well done!

Dave

subd...@gmail.com wrote:
> wow, nicely done!
> Are you taking orders? I could use a sys 11 one :)
>
> Wil
>

[David Schulpius]

Ed, you have way too much time on your hands. I think you need a hobby.
:-) (Really, nice job!).

Dave

[Tim Iskander]

Very cool indeed...
Probably telling you what you already know, but make sure that if you
reverse
bias the solenoids that you have some current limiting in there (a
resisitor or
lamp would work). The protection diode will be (basically) a dead short
and
you could toast it trying to test it!

/Tim

[c...@provide.net]

Oh, i'm bucking the tide here, but this is what i see.
This is a complete waste of time!!! Why do you need a
playfield tester? you *already* have a playfield tester.
(the game!)

If you want to test the coils, use your DMM set to low
ohms and test them. The procedure is in the marvin3m
guides. it takes about 1 minute to do the whole playfield!
it also tests the coil diode at the same time. This
SIMPLE test just using a DMM and about 1 minute of
your time is all you need to do!!!

if you are worried you hooked up a coil wrong, simple
observation will determine that. power is the dual wire
(usually solid color) that daisy chains (except for the
last coil in the chain, one wire). Power goes to the
*banded* diode lug. Again, simply LOOK a the coils
to determine this.

Test the switches manually? WHY???? use the game's built in
switch edge test!!! that's what it is designed for!!

Test the lamps manually? WHY???? Use the game's built in
lamp matrix test!!! I mean if you want to test bulbs
i guess you could use a 5 volt switcher power supply and
a socket to do that outside of the game. but again, why?

[c...@provide.net]

Another coil test you could do, with far less work, is
this. Take a 25 volt game transformer. could be an EM
transformer, or newer. does not matter. find the 25
volt (or higher) AC voltage on the transformer:

1. mount transformer on a small 1' x 1' board.

2. Cut an old extension cord and use the plug/wire
on the transformer to connect it to the mains (120 volts).

3. Connect the two AC transformer 25 volt (or higher)
lugs to a bridge rectifier's AC lugs. Just a standard
bridge rectifier (35 amps 200 volts would be nice).
On one of the bridge's AC lugs put a fuse and fuse holder.
Use a DMM to determine which transformer lugs are 25 (or higher)
volts.

4. run a 3 foot piece of wire from the + and - lugs
of the bridge rectifier. at the ends of the wire, have an
alligator clip. One wire red (+), one black (negative).

5. connect the positive wire to any coil lug which
has a BANDED side of the diode attached. This will
power ALL coils in that daisy chain.

6. power your transformer on.

7. take the black (negative) wire and momentarily
touch the NON-BANDED side of any coil in that daisy chain.
The coil should fire.

There you make a playfield tester in 5 minutes.
For the switches and lamps use the game's switch
and lamp matrix tests!!!

[beaver]

Yes agreed. This is a work in progress, but both this test and the GI
test needs to be done by tailoring the power supply.

For the GI test, I will need to set the voltage limit to 4V. For the
diode test I would need to change the current limit to several hundred
mA.

As I said, work in progress, I may change the circuit to take care of
this in future.

Edward Cheung

[beaver]

There are certainly less elaborate testers one could devise, but I am
the kind of person that likes to build circuits. I have done it since
I was a kid.

My previous hobby (that is similar) is home automation. Instead of
purchasing a commercial system, I hand-built most of the hardware
myself. I put together write-ups of that system also, just like my
current work. I left that hobby when I ran out of things to build.

It only took me about 4 days to design, gather parts, and build this
tester, and I enjoyed doing it. At work, there are techs and
assemblers to build hardware for us, and I don't get the opportunity to
do it. Every one enjoys this hobby differently. For me, it is doing
the work.

Edward Cheung

[K Wilkens]

I agree completely. I find that once there is nothing left to tinker
with I lose interest. I built a mame cabinet and custom control
panel, integrated wireless table tennis scorer into it as well. In
took all my attention for a month of so. As soon as I was finished I
hardly ever play it!

So far my IJ has given me lots to tinker with. I still have a lot
more I could do with it but I'm pacing myself so I don't run out! What
will happen once everything is perfect? I'll strip it all down, send
the play field to PlayfieldRestroration and then get the chance to put
it all back together again :)

K

[Ken]

c...@provide.net wrote in news:1130611532.769968.19580
@g43g2000cwa.googlegroups.com:

> Oh, i'm bucking the tide here, but this is what i see.
> This is a complete waste of time!!! Why do you need a
> playfield tester? you *already* have a playfield tester.
> (the game!)
>

WOW!!! what isn't a waste of time to you? This guy builds a tester that
works for him and you try to crush him. C'mon. I thought we are supposed to
help each other in this group. Why would you start off your reply like
that. If you have a better idea, present it better. I usually, if never
respond to posts like this, but man this one took the cake. Let's realize
that we have very smart people in this group who can share all their
knowledge, both young and old, so let's use it.

Ken

[c...@provide.net]

Believe me, i know plenty about building test fixtures.
>From left to right:
DataEast/System11, System3-7, Bally 77-85, Gameplan, WPC.
Hanging on the wall behind it is Gottlieb System80.
http://www.pinrepair.com/temp/TESTFIX.JPG

Complete *game* on a 2' x 4' board. Tests all switches,
lamps, solenoids, displays for each system. And handles a
variety of different board generations within a system
(for example, on the same fixture i can test System11
with alpha-numeric, and DataEast with alpha or DMD).

I know what's a waste of time. Trust me, i'm the king
of wasting time on buiding test fixtures! Building a playfield
test fixture just doesn't make sense (at least to me).
If you're gonna build a fixture, build a fixture that
does something that you can't do with a DMD in 5 minutes!

Now if it's just a learning experience, Ok fine. But
i still think there are better ways to learn the system
than making a playfield test fixture.

Just my opinion. it means nothing. and it's not meant
to be offensive. if that's how you read it, you read
it wrong.

[Otto]

Edward,

Cool little deal. I wish I had your talent. I'd be bragging too if I could
hook one of those together.

The late model games have built-in test features but who cares?

Congrats on your accomplishment and keep us posted on follow-on generations
and improvements.

The time wasn't wasted if you had fun.

Otto

CARGPB11

My web page: http://home.bellsouth.net/p/PWP-Ottoslanding

"beaver" <e...@edcheung.com> wrote in message
news:1130613644....@g44g2000cwa.googlegroups.com...

[Pinfatuated]

That's pretty cool.

beaver wrote:
> While the clear on my playfield is drying, I decided to build me a
> playfield tester. It allows me to test every switch, light, solenoid
> and associated circuitry safely without risking my CPU board and from
> the comfort of my work bench.

> <<SNIP>>
> Edward Cheung

[Ken S]

Very nice. I know it is very satisfying to crank out something like
that. I have done a few of that type projects myself so I know.
Thanks for sharing.
KS

[jackpot]

That is VERY cool :) I like that ramp repair too.

Neil.

[Steve]

c...@provide.net wrote:
> Oh, i'm bucking the tide here, but this is what i see.
> This is a complete waste of time!!! Why do you need a
> playfield tester? you *already* have a playfield tester.
> (the game!)

Yes, but here you can test and fix the playfield OUT of the game..
which obviously is a TON easier.

Also, your other suggestion works for testing a component, but how
about the rest of the wiring off of it? You could be searching
schematics for ages to find and test in the pins, etc.

I think this idea is great, even tho it does take an investment of time
up front... as it allows you to do all the work and testing in the
comfort of OUTSIDE the cabinet and with ZERO risk to the game
electronics.

Just powering up the machine with a bad playfield could toast things.
Why is doing a little investment protection a bad thing?

[firebir...@yahoo.com]

To all who love to tinker with pinball "whatever works "
now all we need is a assembly line filled with playfields

to the builder of the playfield tester build another rig same a s the
switch but this time it applys voltage to the lamps

[firebir...@yahoo.com]

i see it already does that cool!

[c...@provide.net]

The only way a bad playfield could wreck a boardset is this:

1. coil voltage or flasher voltage shorted to switch matrix.
2. coil voltage shorted to lamp matrix.
3. low ohm coil or shorted coil diode.

For #3 that is easy to test with a DMM. takes about
1 minute to test the entire game with nothing more
than a DMM.

For #1 & #2, i still think that would be easy to test with
a DMM. and i don't think his test fixture will find
these problem anyway, but a DMM will.

So, what exactly is the benefit to a playfield tester?
i mean besides the educational value in making it, i
don't see where it really will help. i guess firing
each coil is cute, but i don't see the need. and besides
you could make a test fixture to do that in about 5 minutes.
testing the GI is also cute. but what for? the worst you'll
find is a shorted GI line. and that's probably easier to
test in the game (using the light bulb in the fuse holder
trick).

Now if the PF tester tested OPTO switches too, including
an under-the-playfield mounted opto board and the LM339 chips,
that would a bit useful. but i don't think his tester does
that either. and again, i think using the game for that testing
is better. and a bad opto switch isn't gonna wreck any
board circuits.

[Steve]

simply because repairing/replacing anything is easier on the 'bench'
then in the machine. It certainly makes sense to know the PF is good
and ready before going through the effort of mounting it.

[Fred Kemper]

Hmm. I think it's quite cool. It isn't a waste of
time at all. The 'journey' is perhaps the value
received in the end. The creator of the device now
has a more intimate understanding of the game for
one example. Looks like he had some fun building it
too, so there is value in that as well.

Fred
TX
CARGPB#8
=====================

[c...@provide.net]

Yes i agree the journey is the party.
But i think a better journey would be to make a
more universal type tester. Playfields are pretty
easy to test without a test fixture. Time could
be better spent. for example, here's some good
test fixture ideas:

1. make a switch matrix box. 64 switches, 8 rows
and columns. have a row and column connector.
then make universal cables for it. one for WPC,
one for Sys11, one for System80, etc. Now you
can plug this box into a CPU board and test
all the switches without a playfield! if there
is a row/col short on a PF, it removes that and
allows you to test the CPU board without the PF.
i made one of these and MAN is it useful! i wish
i made another, one to keep in the tool box.

2. do the same thing with the lamp matrix.
Use an 8x8 LED matrix for the lamp matrix.
this will instantly show if a row or column
is stuck on or off. now as useful as the
switch tester, but still pretty darn cool.

3. solenoid tester. have a single coil (10 ohms)
and a way to go down a row of driver board pins
and test the coil under load. probably not as
useful, but still Ok.

The idea is to make these all universal so you
can plug them into *any* game system.

[Chester Pete]

That is bizare! I have been thinking about building something similar for
myself.
Heres the idea:
instead of making one big test rig, make several small dedicated boxes. They
have to be portable enough to take to a machine and plug them in-situ.
Each box is dedicated to a particular connector for a model (e.g. system 7)
and they monitor the signals going to AND from the solenoids, switch and
lamp matrices.They have a battery and an earth strap
Each box has LEDs which check for particular things.
The solenoid driver connectors
- Check for always on (transistors burned)
- Check for output short circuit
- Memory for an output being grounded (turned on by cycle test and reset by
pushbutton)
- Test for short circuit
The switch matrix and lamp matrix
- check for double triggers and light appropriate LEDs (the cycle test
shows this) - If more than two LEDs fire then an "error" LED fires and
remains on.

The other aspect is that you can make another "set" for ingame play. This
would be used for checking the action of solenoids with a fast acting trip)

What do you think?

<c...@provide.net> wrote in message
news:1130677891....@g49g2000cwa.googlegroups.com...

[beaver]

I bought a non-functioning System 9 CPU board last week from Lloyd
(COW) and intend to repair it (along with building test fixtures for
it).

I already bought the LED matrix displays for the lamp matrix part.

Most likely someone else will respond that I am wasting my time with a
test fixture for that too. But hey, it is _my_ time.

Edward Cheung

[Ken]

Stop thinking......it's his journey........if you create a workbench test
unit that helps YOU! and maybe some others Great...quit with the GOD
complex already....Dam...Are u that bored that you pick apart others who
try something new. The way I view this thread is that you like to destroy
first, then go back and try to tell others how it's supposed to have been
done...YOUR way. I can see why so many in this group have scattered over
the years. To appreciate all this knowledge is a great thing, but to know
it comes from an arrogant source is a shame.

I will be the first to say I apologize if my comments come across as
negative. I appreciate all this group has done for me. I hope this thread
leads to positive things.

Ken

[c...@provide.net]

You see NOW you're talking!
But if you *really* want to do your sys9 test fixture right,
make it system11 compatible. Really the only difference
between sys9 and sys11 is the sys9 CPU board is mounted
upside down! well and sys9 has less ROM space and the
sound sections are different. but other than that, it's
pretty much system11

here's my system9-11 *and* dataeast test fixture:
http://www.pinrepair.com/temp/TESTFIX.JPG
(first one on the left).