Firepower repair
Brian A. Batchelor
fuse if 2J2 connector is interfaced with 2P12 on driver board.
Transistors Q2, Q10, Q12, Q6, Q4 & Q8 all test good. All Coils diodes are
also good. I disconnected all coils and powered up and individually powered
one coil at a time. All lock on.
Suggestions?
Chris
could still have bad predriver transistors, logic chips ahead of these, or
the PIA which drives the logic. If you need any more assistance please let
me know.
Chris
"Brian A. Batchelor" <bbat...@hotmail.com> wrote in message
news:nynld.27520$V41.21716@attbi_s52...
cody chunn
"Chris" <munsonju...@sbcglobal.net> wrote in message
news:EAqld.30302$Al3....@newssvr30.news.prodigy.com...
Brian A. Batchelor
way to eliminate that side and use the playfield switch side to energize the
coils? I thought I could test that by just unplugging 2J13 or 2J12.
I believe that the two 7402 chips are bad, 1 is socketed so i was able to
diode test it out of the game. There are only a couple readings from pin
7(red lead) to the others(black lead) that read over even .3. I also tested
the other one in the game
and it did not give me .5 everywhere either.
I suppose I should get a cople and try it, I'll also replace the 4401
transistor in
that circuit right beside the flipper relay which, by the way, I believe may
be bad also
if I tested it right. I took a 9V battery across the 2 lugs and it did not
close the relay.
Let me know if I'm on the path.
"cody chunn" <OMITc...@comcast.net> wrote in message
news:OPadncDg5oW...@comcast.com...
Ray Johnson - Action Pinball
> It seems that the cpu side of the special solenoids is stuck on, is their
a
> way to eliminate that side and use the playfield switch side to energize
the
> coils? I thought I could test that by just unplugging 2J13 or 2J12.
You probably have a failed chip on the driver board- sending signals out
that tell all the coil circuits to turn on, thus all are energized, and blow
the fuse. Could be PIA chip or could be switch buffer/inverter on the input
switch trigger side of the circuits.
Some probing with a logic probe should find the bad signal and culprit chip,
but takes a little digging around to eliminate and find.
You can remove the switch inputs connector (top left- orange wires?) to
eliminate switches under pop bumpers and slingshot bumpers from the
circuitry. Normally signals from these are used to trigger the circuitry on
the board to activate the coils, when the circuitry is enabled by a signal
from the PIA chip.
If game still activates coils this way, then yes- definitely an on-board
problem. Get out the logic probe.
> I believe that the two 7402 chips are bad, 1 is socketed so i was able to
> diode test it out of the game. There are only a couple readings from pin
> 7(red lead) to the others(black lead) that read over even .3. I also
tested
> the other one in the game
> and it did not give me .5 everywhere either.
Voltage readings on these chips won't tell you much- you need a logic probe
to read a logical "high" or "low" or "floating" signal. And logic truth
table for each chip to see what inputs equal what output. That will tell
you what is right and what is wrong as far as the signals that are there.
You have to know what you are looking for, and looking at, so it's not as
cut-and-dry as it sounds. Experience helps here.
> I suppose I should get a cople and try it, I'll also replace the 4401
transistor in
> that circuit right beside the flipper relay which, by the way, I believe
may be bad also
> if I tested it right. I took a 9V battery across the 2 lugs and it did
not
> close the relay.
The relay has a diode across it's lugs so a battery placed in the wrong
direction will basically be a short circuit across the diode. The other way
it should fire the relay.
You might want to search google.com for past newsgroup articles about board
troubleshooting or possibly find some info at: www.marvin3m.com/fix.htm Too
much really to type here and bring you up to speed in just a few newsgroup
posts.
--
Ray Johnson
Action Pinball & Amusement, LLC
Salt Lake City, Utah USA
Web: www.actionpinball.com
We're serious about pinball. Anything else is just for fun!
PinballMoxie
You need to pickup LEON'S WMS Sys6 Test EPROM. Its truely the only
way to work, Diagnose & Fix the circuit problems on these MPUs. Once
you have that you'll be able to diagnose the problem in 1/2 hour. I
got my Chip from Mark Clayton but there are several other guys here
that will burn it for you, such as John Wart Jr.
Without Leon's Chip and Clay's Guide & Ray's Guide on how to use the
chip I would not have been able to fix any of the WMS games I've
worked on - 10 of them, all with MPU problems that were pretty easy to
diagnose once I got LEON's Test EPROM.
Later
Brian A. Batchelor
Brian
"PinballMoxie" <sc...@farrar.com> wrote in message
news:cc763640.04111...@posting.google.com...
Brian A. Batchelor
guide. Again the game boots and plays as long as i have the special
solenoids desoldered from circuit. In the circuit they stick on and blow
the fuse. I have done some testing but have been led nowhere. Give me a
path to follow.
Brian
"Brian A. Batchelor" <bbat...@hotmail.com> wrote in message
news:Ji0md.509655$mD.165331@attbi_s02...
Ray Johnson - Action Pinball
> Test rom obtained! Thanks John. Now, where can I find ray and clays
> guide. Again the game boots and plays as long as i have the special
> solenoids desoldered from circuit. In the circuit they stick on and blow
> the fuse. I have done some testing but have been led nowhere. Give me a
> path to follow.
If all of the special solenoids come on and stay on (all 4 pops and both
slings) then you have a low-level circuit board problem. I don't know that
you're going to find any "step by step" diagnosis and repair info for this
low-level of a problem, as most of it is basic TTL logic circuitry
troubleshooting that requires a logic probe or oscilloscope and knowing how
to read certain logic signals, truth table, and where and what to look for
based on other signals. This kind of thing can be learned, but it's
something that a lot of people go to school for and takes quite a while to
pick up- not for the faint-of-heart. I could type till my fingers went numb
and still not give you all the info you need to get through it... ;)
I know we don't have anything this low-level on our website
(www.actionpinball.com) but you might check Clay's site for anything that
might be there: www.marvin3m.com/fix.htm And if you can't find any/enough
info, you may want to just consider sending the board out to a qualified
shop for repair- we have a listing of shops on our site at:
www.actionpinball.com in the Game Service & Repair section.
Did you buy a test ROM to help with this problem? If so, I hate to say it
but it won't do anything to help you on this one- test ROM will basically
just cover the immediate CPU-related stuff on the MPU board like CMOS RAM,
RAM, and a few other basics, but nothing on the peripheral circuitry side
with transistors and TTL chips. From my experience, test roms really help
very little, unless you have a MPU board that will boot and run (CPU chip
has to boot/run and be able to access/run the test rom program, or you're
still dead in the water) and then have the "perfect" problem that the test
rom can actually "see" without crashing, and then report accurately. So a
test chip and a lot of luck might produce some results, but they are few and
far between from my experience....
Good luck and hope that helps!
Ray J.
--
PinballMoxie
http://www.marvin3m.com/sys37/index.htm
Assuming you got LEON's Test EPROM from John Wart Jr.
Everything is explained in Clay's Guide but here is a summary:
* You'll want the LEON's Test EPROM in U17
* Power up the board, preferably on your "test bench" with a PC Power
Supply.
* Make sure your MPU is functioning properly - both LEDs should be
flashing off/on in unison every other second
* Turn off the Power Supply & hook up the DRIVER BOARD to your MPU.
* Power up the board again.
* Using the LED (with the Resistor soldered to one end) you can now
focus on testing each of the connectors - this will also help you
verify the Lamp Driver Connectors AND the Solenoid Connectors are
working. SPECIAL SOLENOIDS are J12 & J13 which are located in the
upper left-hand corner of the board.
* My bet is you'll find that you can START diagnosing your problem at
J13 - the LEDs will be ON for each of the pins on the connectors
instead of flashing off/on.
* You can now use your LED (with the Resistor) and start working back
thru the board to find the "fried" component that will need to be
replaced. You will also need the Driver Board Schematics for this
(they are available on the Internet - Clay's Guide has a link to them
at the beginning of the document).
* Chase the solid LED light back thru the schematic until it starts
its Off/On dance. Once you get there, the preceding component is most
likely the culprit. My guess is you have a bad 7408 Chip in either
IC6 or IC7. Maybe even IC8 & IC9 (but doubtful). If none of them are
bad then perhaps a bad PIA in IC5. Remember, it could be several
chips that are not functioning properly.
* Now that you've identified the culprit you gotta replace it! If
you've never done this work before then you could try it yourself -
you gotta learn sometimes. HOWEVER, you take a great chance of
screwing up your Driver Board AND you'll have to spend some money to
purchase the electronics. My advice would be to get one of the guys
on this newsgroup to do the work for you. I recommend Chris Munson
but there are many others that are qualified.
OK - great, you got your board working. Now you gotta ask yourself -
"why did the components fail in the first place?". The answer could
be as simple as old-age...their time had come. However, you could
have an issue with your wiring harness and/or your Special Solenoids
that caused the chip failures. If this is indeed the case then the
moment you plug in that board those chips with pop and smoke like the
4th of July. Special Solenoids are your 2 Sling Shots and the 4 Pop
Bumpers (maybe something else too but I forget off the top of my head
for Firepower). Make sure the switches are not closed, which will
cause a machine-gun firing of the solenoid...if this does happen then
turn OFF the game immediately.
Good Luck. My best advice is to read Clay's guide and follow it. Try
to hook up with a WMS Sys3-7 guy in your area if you can.
Later
someotherguy
I've dealt with all solenoids firing (and usually taking out the solenoid fuse)
is due to bad connection at the 40-pin interconnect.
Richard
On Sat, 13 Nov 2004 11:28:20 -0600, "cody chunn" <OMITc...@comcast.net>
wrote:
Tim Iskander
One of the dreaded SCANBE type sockets... The socket had a
bad/intermittent connection. I fired up the system with the solenoid
power disconnected and went around pushing, nudging, etc on each of the
connectors and socketed chips. When I pushed on the CPU, the system
would "freak out" and do random things before locking up. Lifting the
CPU revealed the culprit. I had already done the 40 pin interconnect,
rom mod, etc and this (knock on wood) has been the final fix!
/Tim