Try to find help for a WMS Flash Sys4 Driver board

Hello Everyone,

Since 3 months, I'm trying to reboot a WMS Sys4 Cpu/Driver (Flash Game)
But, I definitively cannot find help here in Belgium (or french forums).
So I'm not from US, I will try to have my best english possible

So, here's the situation :
On the CPU :
I've replaced all ScanBe sockets with new, and burned the new roms IC14,17,20.
I've refurbished interconnect male (it's in pretty good shape)
No corrosion on this board.

If I try it with leon's test rom, It boot !
I've good flash led sequence ALL TIME

But, When I put driver board, it's locked on...
I've replaced all the 3 PIA's with new Motorola 6821.
And of course The female interconnect (brand new)
Still locked...

After a loooot of differents tests :
On the driver board with only IC5 plugged, it boots (Flash sequence but NO CLICKS)
With only IC10 or IC11 Not booting.

With IC5 + IC10 : Boot ok (Still no clicks)
With IC5 + IC11 : Boot ok (Still no clicks)
With IC10 + IC11 : Locked On...

Is it possible i've got problems with IC 11 ? Or it's pre-driver IC or something else ?

I'm VERY rookie on electronics... So it's very difficult for me, but I really want to try and learn.

I've no Scope, but a logic probe is on the way.

Many thanks for all your response, and take care of you guys.
Greetings from Belgium

#2 4 years ago

BOB

CanadianPinball

Pinside member

Your English is fine, better than some anglophones

Try burning these and running the tests

https://pincoder.ca/

#3 4 years ago

NAV

NeedaVirus

Pinside member

Hi,
First : Many Many thanks for your response !
I've readed the pincoder site (is it yours ? ) And all the tests should I do.

I've burned first rom, 01a.
Of course, LED's working fine ! I've just observed, after maybe 10-15mins, I've just the lower one still flashing... I've shutted power off, and try again after 5 min it's ok again (2flashing LED's) I don't know if this is normal...

I would like to test TP4 Blanking signal, but, Like I said upper post, I'm still waiting for my future logic probe... I've only simple tester by now :-/ (Or the LED like Leon's tech, I don't know if I can trust this for this test... IC23 9+13 and Pin 37 on interconnect powers the led, that's all I know ^^)

I've readed next test 02 Blanking, but now I'm really need that logic probe I think, So I suppose we need to wait for it ?

Just a question, Actually, the boards are on a bench, should I make the tests WITH ou WITHOUT the driver connected ?

Best regards !

#4 4 years ago

???

Robotworkshop

Pinside+ Frequent

https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6

Have you read through these?

https://www.pinwiki.com/wiki/index.php?title=Williams_System_3_-_7

#5 4 years ago

BOB

CanadianPinball

Pinside member

Yes, try with and without the driver board connected.

The site is not mine but I'm sure pincoder can chime in

#6 4 years ago

NAV

NeedaVirus

Pinside member

Hello,

Robotworkshop : Thanks to join the conversation
Yes, I've readed the big post to bulletproof, the power supply is already done, for next things, All I can do is done, I continue reading it following my advancement on the board repairs I think I'm gonna re-read again and again to see if I've missed something...
PinWiki I've readed so many many times, can't see my diagnotics on it :-/ That's the reason I'm here

CanadianPinball : Here's more infos :
I've re-controlled all my IC sockets solder, and other things, I've found a mistake ! On IC5 pins 7-8 where shorted backside the board, whit a liiiiittle rest of solder staticly fixed on the board
Now it's perfect, all pins have good connections and no shorts ^^

I've done a few little more test "like I can" :
With the second Test Prom 02-Blanking :
- CPU Alone : The two led's are strobing fast (I don't know if this is ok ? )
- CPU with Driver : Again the two leds locked on... BUT, if I remove any one of the 3 PIA's (on the driver) it seems to boot (1 Flash on 2Leds -> And Goes OFF.)

Quick test with game proms installed :
- Somethimes, the boards seems to boot correctyl (but in case I put it on the game, games doesn't come up, and no displays.)
- Somethimes, I've the two led's locked on.
- And rarely, I've only the lower one locked on.
- In any case, pressing the diag switch do NOTHING.

I think I'm really stuck now until I receive my Logic Probe :-/

What do you thing ?
Maybe do you want photos or videos of theeses boards ?

Again, many thanks !

#7 4 years ago

???

Robotworkshop

Pinside+ Frequent

Hires pictures of the front and back of both the MPU and driver would help. In some cases people have spotted solder bridges.

So it sounds like you replaced the female portion of the 40 pin. Any cracked solder connections at the .156 headers? Many of those boards had the leads trimmed too short which helped cause that issue.

On early Williams and Bally I have seen 5101 RAM failures often enough where I would check that and also the 6810 RAM chip. Those don’t seem to fail as often but I’ve had to change a few.

#8 4 years ago

???

Robotworkshop

Pinside+ Frequent

It would also help to know if the game was working ok before the 3 months and just stopped booting or if you bought the machine non working with unknown history and have spent the last 3 months trying to get it to work. 1st option at least there is some confidence in the rest of the game. 2nd option you question everything.

What is the condition of the rest of the game? Any wiring hacks or odd things you’ve noticed?

#9 4 years ago

BOB

CanadianPinball

Pinside member

pincoder

#10 4 years ago

BOB

CanadianPinball

Pinside member

5101 Ram can easily be bad, in my experience it's one of the worst chips for electrostatic shock.

As Robot asked above, did you replace the male 40 pins?
Try running the 03 / IC19 test for the 5101

And you can ask questions in this thread, you might get more traction. https://pinside.com/pinball/forum/topic/new-williams-system-6-in-game-test-roms

#11 4 years ago

NAV

NeedaVirus

Pinside member

Hello Everyone !
Week-end is comming so I nearly can get back to work on this !

First, responses to your questions :

YES, i've replaced female connector, with brand new molex.
NO, I didn't replace the male connector, and no sign of cracked solders. (Serioulsly, it's in pretty good shape.)

I've received this game "like this" so, unknow condition, lots of acid leak, but not on cpu, only on driver transistors...
No sign of any hack, cut wires or anything else strange. Pfiuh ! Lucky... 1st thing I do, is rebuild power supply, then cpu, and now I'm stuck with this stupid driver board...

Ok 1st thing I will do tomorrow is new test with 03 Rom.

And finally, here is some pics of theeses boards :
IMG_20200410_110620443_HDR.jpgIMG_20200410_110636433_HDR.jpgIMG_20200410_110644530.jpgIMG_20200410_110707200.jpgIMG_20200410_110725190.jpgIMG_20200410_110742027.jpg

Yes, the female connector is a "Hack" I do myself with molex connector 0.156" because original female is impossible to find here.
And 3rd picture was the most attacked acid zone, I've tried to clean myself

#12 4 years ago

NAV

NeedaVirus

Pinside member

Hello again !

Like I've said, This morning I've tested with 03-Cmos IC19 Test. (And I've cleaned a little my workshop ^^)
And it's working perfectly ! (Top led flashes) I've 'played' a little with the eprom like the Txt said, and no problems.

When I've tried this test with leon test rom, it was also ok 100%

Unfortunately, I'm still waiting for my logic probe (And I think I'm gonna wait more at least 2 weeks...)

Anything else I can do before I ve got this new tool ?

Once again, thanks a lot everyone !

#13 4 years ago

237

slochar

Pinside member

7y 86,550 6,883

If you have an LED, resistor and a piece of solid wire you can make an LED probe... Leon suggested doing this in his instructions for his chip. A cheap made logic probe in a pinch (won't show low, but will show high.)

#14 4 years ago

NAV

NeedaVirus

Pinside member

YES I've this

You think I can go make the test of the 02-Blanking Rom with this stuff ?

#15 4 years ago

NAV

NeedaVirus

Pinside member

Guys I think I've found the (at least one) problem !

If I read and understand correctly the blanking test, It's not ok for me, And cpu is never booting the same way...
Too long to explain, and to be 100% sure of the diag, I've made you a short video : (I've make it quick... Sorry for quality)

We can see the flickering of the leds, or "probe" led, and look, I reboot many times and it never work the same way !
So, what do you think about it ? Blanking is dead ?

#16 4 years ago

NAV

NeedaVirus

Pinside member

Guys ?
Did I make a mistake ?
Am I on the wrong way ?

#17 4 years ago

CCN

pincoder

Hi and sorry for the delay.. I havent been on much lately..

I think you need to focus on the MPU board for now as the 01a-leds test should run forever without problems.. both LEDs should stay alternating. Also, the blanking test should be consistent as well. The resistor and LED setup you have is sufficient and it should always have the same result upon power up. The flickering should not happen there. You can run both of those tests without the driver board and still be fine.

I think the problem is that the CPU chip appears to be crashing and restarting. This could be because of insufficient power getting to the chip, or bad connections etc. Since you have gone over the board many times for cracked joints etc you should check for clean and sufficient power going into the board.

Once you know you have good power, you will need to verify the reset circuit on the MPU board. When the CPU crashes (stops processing instructions) it doesnt automatically reboot itself. The reset circuit is supposed to hold the reset pin low for about the first 0.5 seconds after power up. This is to give the rest of the circuitry time to get clean power and be ready. After this small delay the reset circuit completes its job and allows the pull up resistor (tied to the reset line) to pull up the reset signal to a logic 1. This causes the CPU to boot and start executing code.

You can remove your resistor-LED test circuit from the blanking signal and put it on the reset signal. I believe there is a test point on the MPU board you can connect to. There may even be one on the 40 pin connector. I don't have the schematics in front of me at the moment. You should see the LED come on about 0.5 seconds after you power up and STAY on.

Unfortunately, you probably wont be able to tell if the circuit is "flickering" in this way because it could be happening faster than you can see with an LED. Once you get your logic probe you can set it to "mem" sometime after the half second and the LED on it should stay out.

As for driver board lock ups, its not always the PIA.. sometimes its the logic chips associated with it, but let's focus on getting the MPU board reliable first..

#18 4 years ago

NAV

NeedaVirus

Pinside member

Ok,
For sure, I've got new problems...

Like you mentionned, I've controled again voltages at differents points and method.
I see this morning, my voltage is not so good ... and I don't know why, in the past, it was ok.
I know I not use pro material... But it WAS ok.

Here what I see :
Voltage out of my PC PowerSupply : 5.20DC
Since I put grips on the MPU, this voltage down to 4.40DC ! (Even on the grips itself !)
Of course on IC1 Pin40, I've only 3.14Dc... I think it's not enough.
What can be "drowing" my voltages like that ???

So, I've decided to put back the MPU on the pinball, and see...
No more problems of voltage. 5.05 Stable. No, It's SURE it's not on the mpu this problem... Power supply rebuilded, New connectors, new solders... No, it can't be.

I've tryed again the Blanking test (On the pinball, and without any other boards or connector, just 1J2 plugged):
But, it's still strange on the beginning... Led is flickering a llittle, and then stay on forever. (Trust me, it's not flickering anymore after the power up)

I don't know if this test is now OK or not.

So, here's a quick new video here :

I've tried again to plug MPU + Driver ON THE PINBALL, Still the same issue, MPU seems to boot, but no displays and no attract mode.
So, Definitively, it's still problems on the boards.

I continue to read and try others stuffs waiting for next response

Thanks again.

#19 4 years ago

???

Robotworkshop

Pinside+ Frequent

I would check your jumper cables. Some are garbage. I’ve had two issues with those. Some just have the wire folded back on the insulation and the end sort of crimped onto the end. Those always have bad connections. I’ve taken all of mine apart like that to solder the wire to the end and recrimp to just the plastic as a strain relief.

The other leads I ran across had thin copper wire that looked mostly black. It had a resistance in the wire itself when that should be as close to 0 as possible. Couldn’t carry much current without a noticeable voltage drop. Kept the ends on those and threw the wire in the trash.

#20 4 years ago

NAV

NeedaVirus

Pinside member

Hey,

Yes it's crap... I've reflowed all of them, no difference.
And I finally tested another +5Vdc USB adapter, with grips in end of it, again, 5.15 On the grips, Drop down to 4.40 when plugged to MPU...
But, MPU is booting always and now the 01.Led test is running forever (more than 2hours this time) So, I assume it's good.

By now I will try always all further tests on bench AND on pin to be sure.

Anyway,
I've continued to check some stuff by now : Here it is :

- Measured +12V consistence and it's good : 11.93Vdc, very stable. (For the reset if I've well understanded)
- Measured tensions for this reset, and here it's some problems :
With the LED homemade tester, when I boot up the MPU, I've always one flash and then stay OFF.
With Voltmeter, checked voltages on TP8 (RESET) So, IC1 Pin40 I've only 3.15Vdc, and same on IC18 Pin34. BUT, On 1J1-1 I've got my 4.40Vdc ! (And on this place of course, LED stay ON)
Here's the problem, pretty sure there is something didn't work correctly with RESET Section...

What do you think ?

#21 4 years ago

???

Robotworkshop

Pinside+ Frequent

Are you using a 5v USB adapter as your power source? Those thing vary quite a bit in construction and many may not be able to reliably supply enough current. That will resultin a voltage drop too.

I think some of the issues you have run across may not be issues with your board. Just the way it is being powered on the bench.

I used a triple power adjustable supply on my bench. It has a heavy duty 5v supply with two adjustable. Can adjust the voltage and limit current. Also has displays to show current draw and voltage. Very useful if you work on a lot of electronics. If you’re not then you may want to look at less expensive alternatives.

#22 4 years ago

NAV

NeedaVirus

Pinside member

No no, At basis I work with a PC Power Supply, I've just tried another 5v source to be sure, but no differences.
and it's exactly the same diagnostic in the Pinball itself. (No voltage Drop, but no sign of reset signal ... So Same problem. )

#23 4 years ago

CCN

pincoder

Are you putting "unregulated +5v" on your 1J2-9 pin? It is required for the reset circuit to function properly. My system 6 PSU is showing 10.4 Vdc when disconnected and 10.2 Vdc when connected. Yours should be about the same.

I also agree with Robotworkshop that a USB adapter will not have enough current to supply the entire board so I'm glad you are using the PC power supply. I have also used 400W ATX power supply on the bench just fine. You can connect the 12V of that to 1J2-9.

Also, I recommend connecting the 5Vdc to all three pins on 1J2 (4,5,6) and ground to all pins 1,2,3. This will allow the proper current to flow without stressing wires or pins.

When you also connect the driver board via the 40 pin you also need to supply the same 5V and ground power to the 2J8 pins: +5V on pins 6,8,9 and GND on pins 1,2,3. You may be able to get away with skipping this step as 5V also comes through the 40 pin interconnect, but better to be safe than uncertain.

If power looks good then verify that Q1, Q2, Q3, Q4, Q6, IC5, and all components in the reset circuit are functioning.

#24 4 years ago

NAV

NeedaVirus

Pinside member

Hi there,
Yes, that's what I've done.
Yesterday, replaced ALL Q1-Q6 with no differences.
Testes ALL resistors in reset section, ALL OK.
Still IC5... And I don't have it in stock... Once Again, I'm stuck by now...

But all I can say is, if I remove it, the board doesn't boot anymore.
And IC23 ? Not used for RESET ? I don't have it in stock too...

#25 3 years ago

CCN

pincoder

Do you have your logic probe yet? You need to verify the signal on pin40 of IC1

#26 3 years ago

NAV

NeedaVirus

Pinside member

Unfortunately, not yet
I'm very impatient, of course

2 weeks later

#27 3 years ago

NAV

NeedaVirus

Pinside member

Yaay ! I've got it ! (Better late than never...)
OK, how I'm supposed to use it ?
TTL or CMOS Mode ?

It's new and first time I've got this tool, I'm not pretty sure I know how to use it correctly...

#28 3 years ago

CCN

pincoder

https://www.electronics-notes.com/articles/test-methods/logic-probes/how-to-use-logic-probe-hints-guidelines.php

I have never noticed any real difference between TTL and CMOS mode when using them on equipment from this era of pinball machines, but TTL is normally what I set mine to.

Use it to verify the reset signal. It should start high upon power up, and then go low about half a second later, and STAY low for as long as you run the test.

You can use the MEM function of the probe to determine if it stays low. Start with MEM off, turn the power on, and AFTER it goes low switch the probe to MEM without lifting the probe from the test point. Wait for up to about 10 seconds. If the MEM light comes on, then the probe has detected a blip in the signal and this indicates you have a bad reset circuit.

The documentation for 01b-bus explains the boot process in detail and will give you a better understanding of what should be going on with your machine.

1 week later

#29 3 years ago

NAV

NeedaVirus

Pinside member

Hi there !
Sorry for be late, hard week again...

This morning I've tested my new probe like you decribed it,
Ewh, Don't really understand, because my logic probe works backaround...

I've got Low state for an half second like you described ("0" green LED), and then stay HIGH forever ("1" Red LED) Whithout any "blip"

My Probe is this model :

$_10 (resized).JPG

#30 3 years ago

???

Robotworkshop

Pinside+ Frequent

OP
Quoted from NeedaVirus:
Hi there !
Sorry for be late, hard week again...
This morning I've tested my new probe like you decribed it,
Ewh, Don't really understand, because my logic probe works backaround...
I've got Low state for an half second like you described ("0" green LED), and then stay HIGH forever ("1" Red LED) Whithout any "blip"
My Probe is this model :
[quoted image]

It sounds ok. If you look at the schematic you should see a line above the RESET. When you see a line above the text that means active low. So when it is low the processor is reset and when high it is running. So, it starts out reset and then after a short delay is released and no longer in reset. Sounds good to me.

#31 3 years ago

NAV

NeedaVirus

Pinside member

So, it's probably not the reset section wrong ?
But what could it be so ? Board still refuse to boot.

#32 3 years ago

???

Robotworkshop

Pinside+ Frequent