The Aussie Pinball Arcade
Aussie Pinball Forums => Technical Matters => Pinball Repairs / Problems & Assistance => Topic started by: robm on December 07, 2008, 03:55:48 PM
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Hi,
Just picked this machine up yesterday, $40 from a garage sale - the lights worked but nothing else, got it home and looked at a few very helpful web pages, where one suggested pulling the CPU and driver boards apart and gently clean the connections. Put them back together and it worked!!! I had never seen inside a machine until yesterday and am looking forward to fixing a few lights and switches that aren't working. But first i would like to get the score being displayed.
I did the diagnostic test on the coin door, and all digits on all displays work fine.
I carried out the CPU diagnostic and the two LEDs both flashed - in the manual it says this is either a CMOS RAM or PIA I Display Output failure.
I looked at the diagram and pulled both these out of their holder, cleaned pins and put back in - no change. I have made an assumption that replacing these might be the best way to go (the display output one seems to make sense?) - wondering if there are any suggestions/advice/other testing or places to get parts from.
I am comfortable enough doing basic multimeter testing and soldering but don't know all the electrical or pinball terminology/jargin yet.
Thanks in advance
Rob
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$40 from a garage sale! What a bargain.....
Not sure if you have seen these guides, but they are the 1st reference for any pin repair...
http://www.pinrepair.com/sys37/index.htm
For your display issue:
http://www.pinrepair.com/sys37/index3.htm#display
Re parts, depends on what you need. There are a number of great online shops locally (in Aust) which carry most parts (pinballspareparts.com.au, RTBB.com.au just to name a few!)...
Good luck!
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So displays work in diagnostics but not with switch closures from the playfield?
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Yep, all the display digits work in diagnostics, but stay on 000000 throughout a game...
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Oops, just double checked - Player 1 display stays just 0 (ie first 5 blank) and the other 3 are 000000.
The credit and ball no display (4 digits) works fine.
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Ok we can ignore the missing digits for now, but we need to get scores running a display first - missing digits will be a different problem.
When you close a switch - do you have any sounds at all? Is anything registering on a switch closure?
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As mentioned i'm 1 day new to this stuff.. i assume you mean a switch closure by when the ball hits a target or runs over a button etc... if so, yes is the answer - a couple don't register but 90% make a noise every time they are hit. There also seems to be a score type of system (series of recessed lights - see pic) just above the flippers, this increases as you play the game.
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For the cost of a Flash manual, you've got a clean looking (free) machine there! With the experts on this site you'll get it going in no time!
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Ok what happens is when a switch is closed, it comes into the driver board through connector 2J3. Signal goes through 1 of 2 buffer chips ( ic 15 &16), then into the PIA chip at IC11, up through the 40 pin interconnect and into MPU.
In diagnostics, the driver board is ignored as its the MPU itself that strobes all the digits.
Check IC 15 & 16. These are designed to protect the PIA. They are inverters, so if a high signal is coming in ( 4-5V) then a low is outputed.
Or if low in then high out etc,
any other readings and these chips are gone.
If one of these chips is bad then we have to test PIA also at IC11 - youll need to test this anyway, but always best to start with the simpler stuff first
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I'm following most of that, but am unsure of how to test the ic15 and 16 chips.
I put my multimeter on one side of the green resistor?? thing at the bottom of each chip (underlined in red) and got 4.93V on one side and 0.2 on the other of both.
Is this right or do i need to test the chip itself? and can i do that with just a multimeter?
Thanks very much for the help so far
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Since the last post i have read the guide at http://www.pinrepair.com/begin/index.htm#howdmm on how to test chips.
From what i understand put the red lead of mm on the GND pin of the chip and all the rest (except PWR) should read between 0.4 and 0.6V if i read the guide correctly...
After doing this, on both the IC15 and 16 i got a range of readings - most around 3V, some 4.8 and some 0.
Did i do this right and/or is the chip faulty?
Thanks
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Ok - the green thing is a capacitor, its there to smooth off any signals, youll get 0.2v or so on one side as this side goes to ground.
You need to test the chip itself and yes - can be done with a DMM. A logic probe makes this kind of testing much easier - well worth investing in.
On DC volts - lowest setting. Put the black lead on pin 8 - ground and then go round the chip with the red lead, pin by pin.
IC15;
Input pin 3 should be high, output pin 2 -low
7 high, 6 low
14 high, 15 low
9 high, 10 low
IC16;
3 high, 2 low
7 high, 6 low
14 high, 15 low
9 high, 10 low.
These are the switch inputs - make sure these work OK.
The switch outputs are IC17 & 18 - these are 7406, slightly different configuration, pin 7 is ground.
IC17
Pin 1 high, 2 low
5H, 6L
13H, 12L
9H, 8L
IC18
same as IC17.
Let me know whjat you find, from this we can see if buffer chips are ok and if PIA is working OK
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I cannot believe you picked that up for $40. I mean, I do believe you but I can't fathom how you got it that cheap. Were they totally clueless to what it's worth?
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Creech,
I've always been keen for one, as i thought they would be a good project - but never knew too much about them - i saw this advertised at a garage sale and went straight over. We had to come back 1.5hrs later with the trailer and the lady said about 15 or 20 people ad wanted it since. She and her husband were far from handy at fixing things and said they never used it...so good luck to me!!
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Retropin,
This has been great - thanks a million.
Testing IC15 (8 as GND)
3 3.64
2 1.63
7 3.59
6 3.56
14 1.55
15 4.2
9 4.26
10 4.23
IC 16 (using 1 as GND - 24 pin chip)
3 3.21
2 2.68
7 3.16
6 2.85
14 3.57
15 1.41
9 2.57
10 2.32
Some of these are as you suggested - others are not
IC17 - you mentioned pin 7 as GND, but using circuit diagram it says pin 12 is GND (again 24 pin chip)
Using pin 7 as GND
1 0.24
2 0.2
5 0.6
6 0.16
13 0.66
12 2.26
9 0.47
8 0.14
IC18 (Big PIA Display Output Chip - circuit diagram says 1 is GND?)
using 7 as GND
1 -0.03
2 2.57
5 2.37
6 0.00
13 0.33
12 0.34
9 0.00
8 0.00
I await your instruction.....
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Creech,
I've always been keen for one, as i thought they would be a good project - but never knew too much about them - i saw this advertised at a garage sale and went straight over. We had to come back 1.5hrs later with the trailer and the lady said about 15 or 20 people ad wanted it since. She and her husband were far from handy at fixing things and said they never used it...so good luck to me!!
Yep, everyone deserves a bit of luck some time. Yesterday was your turn. Well done!
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Creech,
I've always been keen for one, as i thought they would be a good project - but never knew too much about them - i saw this advertised at a garage sale and went straight over. We had to come back 1.5hrs later with the trailer and the lady said about 15 or 20 people ad wanted it since. She and her husband were far from handy at fixing things and said they never used it...so good luck to me!!
That is a great story, and something to remember in the future, as this machine won't be last you will pick up ! Well - Not for $40.. %.%
Just looking at the problem, and while waiting for Gavin's advise - have you reseated the connectors going to the Master Display unit ? That's the big display.
Also, the 40 pin interconnect is notorious for causing all sorts of weird problems on Williams machines - while you are waiting, you can gently remove the driver board from the head and then refit... It the problem changes, them that's the first thing I'd work on..Replacing the connectors..
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Yep,
I think i'm already hooked on this pastime - i've learned so much in just a day about these machines - was initially blown away by the technology and workings. I've always been keen for a bargain but this one will have to be up there with the best of them :D
After my initial fix of separating the main and driver boards - i went through and reconnected all plugs and gave each a light clean - am working on adjusting the flippers at the moment as well
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Sorry mate - should have made myself clearer - we are meant to be on the driver board NOT the CPU. We can ignore the CPU for now. We need to see if signals are doing what they are supposed to via the driver board
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OK, my dopey fault - you did mention the driver board, and i didn't notice...
The switch inputs, IC 15 and 16 are all as you suggested - with high's around 4.86v and lows of 0.06v
The outputs however IC 17 and 18 are the complete opposite of your recommendations ie:
Measured
1L 2H
5L 6H
12H 13L
8H 9L
Thanks
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Sounds like the PIA is gone - normal state should be high in and low out for the buffer chips.
If you are getting the readings you are without any switch closures then i recommend replacing the PIA and going from there
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OK thanks for that - is that the main PIA (IC18) on the MPU or the PIA switch matrix (IC11) on the driver board?
Are these things you can get from Jaycar or is it best to order online? - if so, any suggestions.
Thanks heaps
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Hey robm,
congrats on the $40 Flash @ a garage sale. I've been doing the garage sales for years & only ever seen one pin! & yep I bought it, but was alot dearer than $ 40. I did buy a card machine at a garage sale once , ended up selling it to fund my 2nd pin. So I guess I've had some luck too. Keep us posted on your progress.
cheers Steve.
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OK thanks for that - is that the main PIA (IC18) on the MPU or the PIA switch matrix (IC11) on the driver board?
Are these things you can get from Jaycar or is it best to order online? - if so, any suggestions.
Thanks heaps
I'm not sure the local guys carry 6821 PIA.. Maybe someone has one spare ?
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yeh - switch matrix PIA on driver...if we clean up the driver then we can go from there.
I dont have any 6821's spare - if you order some from GPE or jameco then order a few, you can never have enough of these
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OK, I had a brainwave (or delayed thought..) through the night - the fact that player 1's display only showed 0 instead of 000000 was an issue, i assumed (correctly it seems!) that scores were at least in multiples of 10 - therefore the 0 showing wouldn't work. Swapping displays, i found that the error must be on the main display board, since changing a 'good' display (000000) with player 1 also caused it to show 0.
I then looked through the manual and worked out how to play multiplayer (i said i was only new to this) and with great joy discovered that players 2,3 and 4 all score perfectly!!!
So, now i shall try and isolate the problem of the missing 5 digits for player one on the main display board....
Thanks for the help again ^^^
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Certainly good news!
So scores DO register when a switch is closed - the only issue is that Player 1 scores are missing digits??
We can certainly fix that.
But... The outputs on the PIA on driver are not correct, unless you had some switches that were closed.
IF this is an issue it will become evident later down the track as you iron out any other niggles that may be present,
Let me recap.... ALL scores work correctly APART from player 1?
Check the solder joints on this and resolder them all, its common for these to crack and lose signals,
Failing that, the only ic that is for Play1 is IC13, its the only IC that is isolated to Play 1,
But id be looking at the soldering first
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yeh - switch matrix PIA on driver...if we clean up the driver then we can go from there.
I dont have any 6821's spare - if you order some from GPE or jameco then order a few, you can never have enough of these
i get 6821's from here for $3.92. bit cheaper than the US guys with the dollar at the moment...
http://www.futurlec.com.au
just search for 6821 - i can't direct link the component, bloody java..
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I think they are the same as what was on my Sys11B board....If thats the case I have a new one (spare) I'll send if you PM me your details (for nicks!). You'll have to get a socket from Jaycar or similar.
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Great offer Marty. It might not be needed - need to ascertain that no switches were closed at time of testing the switch outputs.
But if switches were in same state when input chips were tested then the PIA is a touch confused as ALL outputs from PIA should have read the same ( outputs on PIA = inputs on switch column drive)
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Marty, thanks heaps for the offer - i'll see whether i require the part....
Retropin,
Yes that is correct - all scores work correctly except player 1
When i swap another player's score display and connect to player 1 plug, i have the same issue ie: just the end 0 displayed (not 000000). So i assume the problem is not the actual display and has to be at the main display board end (or driver board).
I pulled the main display board off and checked all connections, and everything seemed OK to my novice eye....
I also carried out the Switch Test (03) and it says any stuck switches will be displayed - nothing was displayed and everything seemed fine - the only issue i have is the 3 bank drop target won't pop back up after all 3 have been dropped (fine for a new game though) - i pulled this apart and the horse shoe wiper thingy is broken on one - but i don't think this would affect the player 1 not scoring issue.
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I have to say it "Score of the century" well done !!!! #*# :lol
Just a quicky,:
Unplug/plugin the score display #1 connector on & off the display about 10 times...
The abrasion of each plug/unplug will clean the connectors to make them conduct again.
You might be lucky to see score #1 come to life again....it might be *that* simple %$%
Also unplug/plugin the connector on the main score board too, maybe it's not passing score #1 addressing info through to score #1 ??
(i've fixed a few machines this way myself).
once again, what an abolsute score (no pun intended).
Marty.