Tips para chequear pinball-Marcelo Blanco Pinball

Tips para chequear pinball-Marcelo Blanco Pinball


A Multimeter is something very elementary and basic for a technician
But for the non technician he doesn´t know how to start with it

And it´s an invaluable tool for diagnose
and to start checking avoiding to make things worst!
Which is something pretty important!
So what I wanted to show you a little bit
it´s that basically when you buy a pinball
and you don´t know if it´s in good shape
Or you just received it and the guy told you that it ¨works¨
That it did turn on!
Because the term “It turns on” it ends up being quite vague
“Turns on”:Does it light up?, Does the displays turn on?Can you play it?
I´m going to give you a few tips on checking out
on a game before you make things worst because something is wrong!

It´s very simple and quite basic but it will help you to solve
or at least to avoid a bigger problem
on the MPU, on video boards on newer machines
that sometimes end up being a problem to find replacements even for sound boards
I´m gonna show you some tips
I got here a TOTAN
from Williams
And a Data East game
It will cover more or less Data East machines in general

and a little bit also on Williams/Bally WPC WPC95
And will see if we can transport it to some different brands and models
well this are boards for a WPC95
TOTAN in this case

This is the audio/video board
In this game generation you have a combo DCS sound that first came with the Indiana Jones pinball
and also video support
which now is a little bit different in design from the WPC games
On the bottom part of the cabinet we have the power supply/driver combo board
We have the power supply section
and the coil and lamp driver circuits
Those are the general light control
And here we have the MPU
MPU is pretty much like a WPC one
This is a WPC 95 with a security Chip

which tends to have some issues
Security chip was used to avoid swapping boards from game to game
I´ve never understood quite good why they did this…

Let´s see. You have the power supply circuits here
but when you don´t know
if it´s working good for sure
then you have to think that a power supply issue can damage any other board
video boad or MPU board
So the first thing to do …at least this is my advice…

is to unplug the power wires coming out of the power supply to the other boards
Why?Becuase in that way
we can check out voltages on the power supply without putting the other boards on risk
In this case power out plug it this connector
On WPC machines is pretty much the same
But it´s below the large data cable that goes from MPU to Driver board
and tells which coil or lamp to turn on

On WPC games, for instance a Guilligans, an Addams, Terminator and so
power connector is below the data cable
and it´s below the data cable on the power board too
So what it´s preffered is to unplug this
because in that way we take off power supply to all the rest of the boards

but the small boards you might have underneath the playfield
most of the times playfield boards use 12volts and they have no major issues and are less sensitive to voltage problems
But you can unplug it anyway
On WPC95 games you have those plugs on the upper side
There are unplugged already here
Usually you´ll find a black wire and a grey/yellow wire
Grey/yellow carries 12volts and black wire is ground

On WPC95 power board there it´s printed where the plug goes to

Unplugging that we guarantee that
we can plug the game and test power supply
and avoiding to “touch” with power the other boards

Video/Audio board and MPU board will have no power
Take care with the display as it will still have high voltage

In that case if you are affraid to touch high voltage handling the display
just unplug it.
Please do all this things with the machine turned OFF
just in case!
Because you can make a bad contact or miss the aligment on the plugs and damage those boards

You better turn off the game
and you avoid any damage
Once it´s unplugged
you turn on the game
and the first thing you´ll see are the leds turn on

You´ll see the markings on the board showing what indicates each led
This one reads “12 volts”
This is the 5 volt one
This is 12 volt unregulated
which is used for certain circuits
and it´s the previous of the 5volt regulator
It´s used also for motors and some other stuff
and even as the led turns on it doesn´t indicate propper power values
but you know it´s in
Then we should measure it
But once it turned on and no fuse blew
we can plug the rest of the boards
But first we should measure for propper power supply
And you have Test Point to do so
This is our ground reference
We plug our black wire from the multimeter
I´ll do a small video on how to use a multimeter!
And these are the other ones.
Most of the time you´ll see that each TP is marked
Here you have 5Volt TP and 12volt for the swithc matrix

This is the power supply for the lamp matrix
Here you have unregulated 12volts
All those voltages must be right
“5 volts” must be as close to 5volt as possible.
it must be between 5.02, 4.98
4.97…
because is pretty important that 5 volt supply is good
or the MPU will constantly reboot
Why does it do that? Because if values are not right
logic states on ics and processor
might not be accurate
so software can crash as perhaps a “1” is read as a “0”
so to avoid that

when the board detects that voltage is off
it will cause a reset so software stops running as it might cause a coil to pulse
or make some lights stuck and so
so that´s why WPC and WPC95

tends to have reset issues because as soon as the power supply
has a bad contact, a regulator problem or whatever
the first thing it will do as soon as voltage drops from 4.98
to 4.96 is to reset MPU
And those are the intermitent resets we have
most commonly when you press flipper buttons as that´s the moment when you have more power consumption
As you have a bigger power drain
voltage drops a little bit and that might affect power supply
But the most important thing is as we have 5 volts and 12 volts
we can now plug MPU and video board back on

because we know that we have no problems with it
Let´s see the same connectors on a Data east
so you have the same reference
On Data East we have the sound board at the bottom
This one or a very similar one
This board which is called PPB (an intermediate board)

That makes some coil bank switch
it has some resistors for the flash lamps
and then there is the MPU and the Power Supply
In this case video board is mounted on the back of the display
It´s a microprocessor board
that controls display board independently

And then we have the 5volt connector
This is the power supply IN plug
And here the output power is this connector

And as you can see…as DATAEAST used very much as a reference Williams Sys 11
it´s almost the same
color scheme. So you have black wires
and grey/white wires. Those are the 5volt lines
that goes to the rest of the game
so ideally we unplug this large conector
and then test the power supply unpluged
and it´s almost the same. We have test points
showing you values. 5volts
12v, -12v
and display voltages.
Display voltages are more easily measured on the connector

Once we are sure that 5volt and 12volts are OK
you can plug MPU board and continue testing
On the same way on both brands of games
I´ll do the same with the coil
and switch connectors. I wouldn´t care too much for the controled lights
If the MPU has
some shorted transistor
you will turn the game on and you will blow a fuse or get a coil stuck

so it´s better to left coils unplugged
on Data Easts this are the coils output
this is the switch matrix connectors
and these are the controled lights output. We can leave this connected
So by unpluging switch matrix
and coils we assure to start MPU without any further
problem.
Sometimes due to a bad assembling
or because you have a game that´s been in storage
or was misshandled
there might be a switch making contact with some lamp
or a coil wire
and it could blow up your switch matrix circuits

Here is just the same. It´s a little bit more complex as you have way more coils
but here you have your connectors for the coils
and it´s more or less like a WPC game
and here you have switch connectors

direct switch inputs are for the cabinet door

you can leave them connected
but you should unplug the other two

by unpluging
we assure that any issue with the playfield
due to mishandling
won´t make that a different voltage
hits the switch matrix and ruins MPU
That would be the basics
to test a machine.
And once we have the MPU working
we can get into diagnose and tests

and then we start plugin in one by one
the coil plugs and check that no coil gets stuck on due to bad transistor for instance

and then we plug back switch matrix
but first we check that there isn´t any switch touching a coil wire or lamp socket

This is a classic example of a dangerous switch that´s too close
This is a slingshot switch on a Safe Cracker pinball

and really close to it there is a lamp socket
a lamp socket for a general illumination circuit
which are usually very close
so we have to check that the switch terminal doesnt touch lamp socket
because that would be a mess

you get AC voltage from the lamps straight to the switch matrix
and we might blow a ULN2803
which is a transistor array
8 transistors in a single package
on Data east you´ll see that there are actually 8 transistors
these ones
this is the switch matrix drives

On WPC games you have ULN2803
So by checking that switches
are not touching other circuits
we plug one by one each switch connector
so in this simple way and very easy
we avoid
that any issue unknown on the game
will end up being a bigger problem
On 80´s Bally games
It´s a little bit more difficult to unplug 5v supply to the boards
and I´ll show you why
we have here two Bally boards in pretty rough shape but they´ll do the job anyway
This is a Bally driver/power board
this is our 5v section
and this is the display voltage
So voltage inputs and outputs are located on this large connector
We have all the power inputs
and also the 5 volt supply to the other boards

so there is not a simple connector that we can unplug and take off the 5v supply to the other boards

So what we have to do is checking out first the voltages at the power supply
We unplug soundboard connector
and MPU power input
This is a Bally MPU board (the same for a stern 1980s)
and we unplug this connector
On Bally and Stern MPUs
you have power input: 5volts, 12 volts and 43 volts
from the coils that MPU uses for checking that we have power for the coils
and it uses it for Zero voltage crossing detection

as coil voltage is rectified but not filtered

Also there is coil data to the power/driver board

By unpluging this
we asure that there is no power on the MPU
We unplug the sound board too

and we are confident that a erroneous voltage wont get to those boards
So we measure voltages on power supply board
we have here our ground test point
and here there are 5volt

on one of these TPs. You´ll have to check as there is some differences between power supply board models

It´s pretty easy. You have 12 volt unregulated
and 5 volts
Once we are confident that 5 volts are OK
we can plug back MPU and check if it works
And you can do the same for the switch matrix here
In this board switch matrix are conected to these two connectors
One for the door switches and one for the playfield
this large connector
sometimes are used for sound…
but it´s for displays mainly
Always is more important to prevent further problems
if we don´t know in which condition is the machine
because a power supply problem which is pretty common
won´t damage any other board
80´s Ballys are a lot less problematic for 5volt supply
in this case this capacitor should be replaced as it´s 40 years old

but most of the times there are no bigger issues
I hope this video has been usefull
I´ll be doing another video soon talking about multimeter use
which I think is very important
so you know how to use it
A very basic and easy to use tool
and will allow us to diagnose a lot of game problems
So see you on the next video!

6 Comments on “Tips para chequear pinball-Marcelo Blanco Pinball”

  1. hola marcelo una consulta vos rutinas pinball o mantenimiento . yo no entiendo mucho como meterle mano , estoy en cap fed gracias

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