Thanks to Tuborg for showing up tonight with a whole workbench worth of tools and supplies. We knocked our heads together and finally figured out how to crimp. She's not pretty, but voltage is flowing!

Unfortunately, the MPU isn't booting. The LED stays on. According to the 'guide' this could mean a lot of things, but I just had the board repaired a couple months ago, and it booted on the test bench. So I checked TP2, and I'm reading ~15 volts. It should be 12, but is it within that acceptable range? What could cause it to be off, the solenoid board (the guide mentions something about the circuit going through there).

HELP! I'm sooooo close!  

Thanks!

What game is this? The 12v doesn't really affect the IC's. They run on 5v. It sounds like you're talking about a Bally board. If so, reseat your roms first (U2 through U6). Then reseat your U9, U10 and U11. Are you testing the board on the bench or in the game? If in the game, just use J4 on the MPU until you get it booting. You don't need the other connectors attached and disconnecting them will rule out any off-board issues causing the MPU to lock up.

Sorry, it's my Six Million Dollar Man. And it's in the backbox, not the test bench.

Check the voltages on the Solenoid board and the check J4 of the MPU. If it boots on the bench, it should work in the game, unless there is a problem in the supply chain. I suspect the Solenoid board.

As the others have stated, measure the +5V on the MPU itself, then report the reading.

Issue could be:
- no or low (or rippled) +5V supply
- bad connector or cold solder joint on Solenoid Driver
- bad chip sockets on MPU (U2, U6, U11 to check first).

- Sylvain.

Unplug all boards except J4 on the MPU (even the displays), and start it up.

If you get your seven flashes, plug in one board at a time and turn it on to see what happens. Same goes for the displays. I had one that was goofy on one machine and it caused the MPU to lock on.

Good job Jonny.  I'm sure if we taped this for youtube we could have made a few laugh.   Not quite as bad as Hanks Pinball Tips.  


You did it all.   Is it really not pretty - you were doing fine before I left!

Thanks for all the tips. I took the board out of the machine and gave it to my 'guy' at work to take a second look at it this weekend. While reseating a couple of the ICs, some legs fell off. I replaced the ICs with new ones I got from Dave Astill, but obviously the board is not as 'perfect' as I thought it was. I should get it back on Monday, I'll try the above tips then.

Ok, I had it tested out, and the MPU worked like a champ on the test bench. I realized that the top right corner wasn't screwed to the backbox, so the ground wasn't making contact. I did that, and now the LED is a lot brighter, and I have new readings. Game still doesn't boot, LED remains solid.

Here's where I'm at now:
TP1: 1.460 V
TP2: 15.49V
TP3: 6.1 mV?
TP4: GND
TP5: 1.465 V
TP6: 5.74 V

Also, the bottom left corner isn't connected to the backbox because that part of the backbox got corroded so there's some electrical tape covering it. Does it matter?

I also tried what Sparky suggested. I unplugged all the boards, except J3 on the driver board (otherwise the LED doesn't turn on), and still have the same problem.

A -35 MPU should read:

- TP2: +12V or so
- TP3: +21.5V or so
- TP4: GND
- TP5: +5V

You have the manual and schematics?
This is shown on the MPU page.

The +12 drives the LED.
The +5V is required and is the main supply voltage for the board.

Go back to the solenoid driver and measure/tell us what you read on TP1, TP3.

- Sylvain.

On the solenoid/driver board:
TP1: 5.24 V
TP3: 5.15 V

So the +5 does not seem to make it to your MPU.
How's the J4 connector (pins in the housing?)
If any corrosion there, it could cause this.

Quoted from sylvain

So the +5 does not seem to make it to your MPU.
How's the J4 connector (pins in the housing?)
If any corrosion there, it could cause this.

Good question, how do I test it?

I just poked my DMM into pin 16 on J4, and the LED started blinking!! OMG, Sylvain, you're a bloody genius!

Now what? Anyone got a connector housing and some terminals that I can buy from you?

Update: If I leave my DMM jammed into the connector, I can get the MPU to six blinks. Not enough eh? Back to pinrepair.com!

You need to read +21.5V or so at TP3 for the zero crossing detector to work,
to complete the 7th and last LED flash.

Make sure the solenoid fuse is good on the power supply, as well as the fuse
under the playfield. If all good, probably another bad corroded pin in J4...

- Sylvain.

Fuse under the playfield?! It's dead Jim! (And I don't have any 1A fuses )

Jon

I have some 1A and those other parts if you want to make a road trip.

ME

I have some also if needed.

I have some if you wanna drop by tonight (before 10pm)

Quoted from Tuborg

I have some if you wanna drop by tonight (before 10pm)

Oh no, I don't have a car! I'll take you up on it if my wife gets home in time

Update: My wife is coming to pick it up. This is exciting!!

Ok, replaced the under playfield fuse (thanks Tuborg!!). When I turn the machine on, the outlane diverter coil engages. I guess that's what blew the fuse? So I disconnected that coil.

Unfortunately, still not getting anything at TP3 I suppose the connector is corroded from the battery leak. I got the header pins replaced, but I guess I need to do the connector too. Do I need to order it from GPE? Or does anyone here have it?

What kind of connector do I need? Not the usual 0.156" molex. Is crimping it different? I assume I need the 0.1" connector, some brass terminals, and the right crimper. Is that right? Can I find these at a local electronics store, or should I order from GPE? I'd really like to get this game working by the weekend, I'm having some friends over.

The outlane diverter coil is made to stay on for a while.
Unless burned, it should not be the cause of the blown 1A SB fuse under the PF.

Check the new fuse under the PF in case it blew again.
Was the Solenoid Driver board checked for possible shorted transistors?

Most likely you will need to repin most or all of the 0.100 pins in the J4 MPU connector housing.
Not only J4 supplies power to the MPU, but it also outputs the solenoid commands
to the solenoid driver, in turn to the coils...

- Sylvain.

Where are the fat bastards with their documentary camera?  THis would make a great first episode....

Quoted from Tuborg

Where are the fat bastards with their documentary camera?  THis would make a great first episode....

It is only a 20-minute show...

My approach on this machine would be rather simple... OVERKILL. I would change EVERY connector pin and EVERY header pin if possible. These are Bally machines' Achilles' heel.

In fact, FIRST you change the connector pins, THEN the header pins. Connector pins are more subject to problems, as they are the thinner metal.

These connectors had a life expectancy of 5 years... your machine is 31 years old.

The under-playfield fuse wouldn't have anything to do with the mpu not finishing the last flash. But if it was blown it needed to be changed anyway.

Check for voltage on the left and right side of R133 near J4 on the MPU. It should be 43vdc on the left side and 21vdc on the right.

If you read 43vdc on the left and 0vdc on the right, you have a bad R133 which will prevent the last flash from happening.

If you read 0vdc at both sides, then, as others have stated, you have a bad connector pin on J4 (assuming the solenoid power fuse - F4/5A - and BR2 on the power supply are good).

Changing the headers and terminals in J4 on the mpu is a good idea. You could also measure for 43vdc at one of the J4 pins (I can't remember which one). This would tell you if your coil voltage (43vdc) is at least reaching the board - this is what is required for the last flash.

Quoted from cooke

The under-playfield fuse wouldn't have anything to do with the mpu not finishing the last flash. But if it was blown it needed to be changed anyway.

Check for voltage on the left and right side of R133 near J4 on the MPU. It should be 43vdc on the left side and 21vdc on the right.

If you read 43vdc on the left and 0vdc on the right, you have a bad R133 which will prevent the last flash from happening.

If you read 0vdc at both sides, then, as others have stated, you have a bad connector pin on J4 (assuming the solenoid power fuse - F4/5A - and BR2 on the power supply are good).

Changing the headers and terminals in J4 on the mpu is a good idea. You could also measure for 43vdc at one of the J4 pins (I can't remember which one). This would tell you if your coil voltage (43vdc) is at least reaching the board - this is what is required for the last flash.

I did as you said, and I read 43V on both sides of the resistor (R113, I think). That's not right, voltages are supposed to drop across resistors. Should be easy enough to fix. I just need a 2K Ohm resistor.

Just took a look at the schematic with some other guys at work and we've reached the conclusion that it's probably not a bad resistor. The only way to explain that there's 43V on the right side of the resistor, and 0V at TP3 is that the trace must be severed at some point along the way, probably due to corrosion. Yay!

Well it sounds like R133 is shorted. You'll need to replace it anyway. Then just follow the trace and see what you find between R133 and TP3.

Quoted from cooke

Well it sounds like R133 is shorted. You'll need to replace it anyway. Then just follow the trace and see what you find between R133 and TP3.

I don't think it works like that. If the trace is shorted between the resistor and the Zero Crossing Detector section, then there won't be a load. Instead, the current will just go to ground at C1, causing 43V to be read on both sides of the resistor. I'm not sure if the resistor's bad.

Have you checked the resistance of R133? It should be 2k ohms.

Quoted from jonny_eh

I don't think it works like that. If the trace is shorted between the resistor and the Zero Crossing Detector section, then there won't be a load. Instead, the current will just go to ground at C1, causing 43V to be read on both sides of the resistor. I'm not sure if the resistor's bad.

Quoted from cooke

Have you checked the resistance of R133? It should be 2k ohms.

That, I have not and will do first thing when I get back home.

I have never seen these type of resistors shorting. Drifting in value yes, but not shorting.

If you measure the same voltage on both sides of the resistor, it most likely
indicates either no current flowing through it, or a short under the part.

With the readings you are giving us across R113, most likely there is either an open trace,
or an open/bad R16 (also 2K) that should be sinking this +43V to ground (thus is why
the TP3 should read +21.5: half of 43V, being in the middle of two equal-value resistors
between the supply and the ground).

                                   TP3
+43-> ---R113 (2K) ----o---- to zero crossing detector input
                                     |
                                  R16 (2k)
                                     |
                                   GND


Cheers,
- Sylvain.

But the fact that I'm reading 43V before TP3, but a REALLY low value at TP3 probably means something, right? Something must be happening between the right leg of R113 and TP3. They 'should' be the same value, no?

Yes, the measured voltage between the right leg of R113 and TP3 should be the same, as per the MPU diagram.

As indicated above, check the trace, as well as double-check that you are actually measuring TP3

I am not home now to check, but is that trace going via a thru hole (from copper side to component side) ?
These sometimes are bad, especially with corrosion involved...

- Sylvain.

No idea, I too have to get home first to check.

Ya, I suck. I tested again, and I do NOT have 43V on the right side of R113, I have 43 mV! I need an analog DMM

Anyways, R113 gives me a reading of 0 Ohm, and the skin around the middle is missing. This makes me think that Cooke was right, sorry for doubting you! I also tested R16 for good measure, and it's giving me about 1M Ohm. R17 tested out ok at 130-150 K Ohm, so I think it's just those two resistors that are bad. Or is testing it in circuit no good?

What voltage are you reading on the _left_ side of R113 ?

If 43 mV, then the issue is the J4 pins inside the housing, or the fuse under the PF.
If 43V, then R113 is opened (and not 0).

If R113 was truly 0 ohms, then the voltage on both sides should be *exactly* the same.
...Something is still not quite right here.
If that resistor is burned, it might be opened (infinite resistance), not a short/0 ohms.

Yes, measuring a component in-circuit (such as resistors) might give a lower value
reading, due to other components/paths in parallel to the device being measured
(which lowers the measured equivalent resistance, as in parallel).

So... no garantees that R113 is really bad yet, unless someone already replaced it
by a zero ohm jumper one. That would have fried R16 (which now measures open, 1M)
and possibly also the zero crossing input, although there is a protection diode CR49
clamping the input voltage to the zero crossing detector U14, pin 14.

You can measure R113 out-of-circuit by unsoldering or clipping one end of the resistor,
then measuring its resistance value.

In any case, before taking any resistance measurements, make sure power is off on
the pinball machine,  with J4 disconnected, to ensure no 'stray' voltage is fooling
(or damaging) your DMM on the ohms setting.

- Sylvain.

The left side of R113 is definitely 43V. I also took the board out to take those resistance measurements.

Can I replace the two bad 2K resistors with 2.2K resistors? The resistor packs at the Source only contains 1K, 1.8K and 2.2K, not 2K. Otherwise I'll have to go to a real electronics store, but it'll be really inconvenient because of their piss poor hours.

Also, I'm kinda curious now what the zero cross detector is doing. Anyone feel like giving an electronics lesson? A co-worker says it detects when a sine-wave crosses zero, but he obviously doesn't know why it would do that on this board.

Using 2.2K resistors is fine. I recommend that 1/2 watt ones be used instead of the original 1/4 watt.

I cannot clearly recall what the zero detector is used for.
However, I seem to recall that it has to do with the turning on (and maybe off)
of the controlled lamps. e.g. doing so at the proper time during the rectified but not filtered
AC pulse so that the lamps would be turned on near the zero volt cycle, to avoid high in-rush
current to bulbs (useful for the drive triacs and the bulbs!), and also to reduce harmonics
(I remember cheap lamp dimmers in our homes causing a lot of interference noise
in AM radios since many cheap dimmers cut/hash the AC pulse to the bulb pretty poorly).

- Sylvain.

Ok, I bought the 1/4 watt resistors since 1/2 watt ones weren't available, oh well. I'll try it out tonight if I get time to hack work on the board.

W00t! It boots!

All the displays work and are STRONG. All SEVEN of them!

Bummer:
-No sound (other than interference from the displays)
-No coils

The start button starts a game (and adds players), and the coin switches add players.

Thanks everyone for your help! ALL of you! Smooch

Quoted from jonny_eh

W00t! It boots!

Good job ...

Now update the title of this post !  

Congrats,
Steph

Quoted from Steph

Good job ...

Now update the title of this post !  

Congrats,
Steph

Done!

BTW, I suspect the solenoids are not working do to connector corrosion on connector J4, but I don't have a replacement Can these be bought at local electronics stores?

How would I test that the solenoid board is not the problem? What about sound? So many new problems to explore! So exciting!

Sylvain!

Another R113 gone bad - I hate to say I told you so.... It happens!

Congratulations on getting the game started Jonny, this is fustrating I know, but the experience you are gaining can only help things in the future! Some people think these Bally games are tough - you just gotta stick with them until everything works out..... you'll know just what to look for next time.

Once again CONGRATULATIONS!

Thanks Bally Boy. It can be frustrating at times, but it's totally worth it. I'm having a lot of fun.

If only I could get the solenoids working, I could actually play a game!! Anyone in ottawa have a 19-pin 0.1" molex connector housing? (plus terminals)

Oh, and the 100s digit on the 2nd player score display isn't working. Only one digit out of 7x6=42 ain't bad! I'll probably just swap it with player 6. When am I ever gonna get 6 people playing? Maybe next league meeting?

While R113 was bad (not 0 Ohm, OL Ohm yeesh I'm dumb), so was R16. R16 snapped in half while removing it.

I never mentioned before, but the flippers work when a game is started. The flipper relay is a 'continuous' solenoid and seems to be driven just fine by U11 on the MPU. Why is it the momentary solenoids and sound don't work? How should I trouble shoot this?

Clay's guide just says to check the under-playfield fuse, but it's fine. I can also manually active every coil by jumpering the tab of each coils' transistor on the board to ground.

I've removed and cleaned the J4 contacts, and they look fine. The game seems to boot just fine everytime now.

Also, it turned out that pushing 'start' would also add a couple credits. How does it do that? I don't see any hacks to allow free play, it's cool regardless. Unfortunately, at some point the start button stopped working

I think I know what the problem is. I removed chip U11 and discovered that pin 19 has a leg stuck in there! It's small, but it's there. How do I get it out, it's so small!

If all your coils but your flippers don't work and they work when shorted to ground, I'd be starting to look at the headers and connector pins on J3 (top right) of the driver board. This is a typically problematic connector. This problem is probably not a MPU connector or PIA problem, but I could be wrong. The reason I doubt it's a MPU problem is because your flippers are working; that means that the MPU is telling the driver board to turn on the flipper enable relay (a coil, just like the rest). Does the lockout coil and the knocker work when in test mode but none of the other coils? If so, then I'd reeaaally be taking a closer look at that under-playfield fuse. Perhaps swap it anyway!

Well, got the pin out, swapped u10 and u11, but problem remains.

Only flipper works, no coil lockout or knocker.

The playfield fuse is fine. I replaced it myself. The Outland diverter activates, didn't before replacing the fuse.  

For those who still care (who doesn't?!) I've made progress!

I finally pulled out all the documentation for the two chips (MPU-U11: 6821 and Solenoid-U2: 74LIS4) that talk to each other. I figured that if I'm seeing no coils going, it's got to be the chip enable signal not getting from U11 on the MPU to U2 on the solenoid board. So I methodically tested each step of the connection using my DMM's continuity test. U2 to header pin (good), U2 to MPU J4 connector pin 10 (good), U2 to R106 on the MPU (bad), header pin J4 pin 10 to R106 (good), R106 to U11 (good), MPU J4 connector pin 10 to R106 (bad).  By means of elementary deduction my dear Watson, the problem must be between the connector and the header pin (shock!). I pull out terminal from the connector for pin 10. It looks clean. I rub it with some alcohol, make it shiny, then realize it looks a little 'compressed', maybe it's not pushing against the pin? I pull it out a bit... and it falls off   I guess I need those new terminals already!!

So, to test my theory, I put the machine into coil test mode, touch the now loose wire to R106 and yay! Coils are working!!!! Not only that, sound works in sound test mode too!!!!!

This has all been very educational, thanks again to everyone for suffering through it with me, I hope others are learning too.

I've been following this with a great deal of interest.  Thanks for sharing!

Quoted from jonny_eh

...By means of elementary deduction my dear Watson, the problem must be between the connector and the header pin (shock!). I pull out terminal from the connector for pin 10. It looks clean. I rub it with some alcohol, make it shiny, then realize it looks a little 'compressed', maybe it's not pushing against the pin? I pull it out a bit... and it falls off   I guess I need those new terminals already!!

So, to test my theory, I put the machine into coil test mode, touch the now loose wire to R106 and yay! Coils are working!!!! Not only that, sound works in sound test mode too!!!!!

Quoted from Sparky

...My approach on this machine would be rather simple... OVERKILL. I would change EVERY connector pin and EVERY header pin if possible. These are Bally machines' Achilles' heel.

In fact, FIRST you change the connector pins, THEN the header pins. Connector pins are more subject to problems, as they are the thinner metal.

These connectors had a life expectancy of 5 years... your machine is 31 years old.

Rule of thumb: When you get your first SS Bally, contact ed at GPE and order yourself a lot of 0.156" Trifurcon connector terminals.

Quoted from Sparky

Rule of thumb: When you get your first SS Bally, contact ed at GPE and order yourself a lot of 0.156" Trifurcon connector terminals.

But his problem was with the .100" terminals and connectors.

Thanks for posting, Jon. Glad you worked it out.

I'm pretty sure I have some 0.100's at home too Jonny.    I can check tonight if interested....

Quoted from sylvain

Check the new fuse under the PF in case it blew again.
Was the Solenoid Driver board checked for possible shorted transistors?

Most likely you will need to repin most or all of the 0.100 pins in the J4 MPU connector housing.
Not only J4 supplies power to the MPU, but it also outputs the solenoid commands
to the solenoid driver, in turn to the coils...

- Sylvain.

Someone else had already pinpointed the issue!

Ya, I figured Sylvain and Sparky were right. I spent Saturday morning calling all the local electronics stores looking for 0.100" connectors. I realize now I just needed terminals. But I was still hoping the problem was lying elsewhere (kind of like how Dr. House will test for treatable diseases before a more likely but fatal one). It pays to methodical, to understand the signals being transmitted, and working backwords to see where the connection goes wrong.

Doug, can I take you up on your offer for terminals? I'd also need to borrow your crimper, mine doesn't do 0.100".

Quoted from jonny_eh

Doug, can I take you up on your offer for terminals? I'd also need to borrow your crimper, mine doesn't do 0.100".

For sure - I can check around 7pm or so tonight if I have them.   I believe my crimper does 0.100 (the C / D settings) for all I know.   I'll PM you...

Quoted from jonny_eh

Ya, I figured Sylvain and Sparky were right. I spent Saturday morning calling all the local electronics stores looking for 0.100" connectors. I realize now I just needed terminals. But I was still hoping the problem was lying elsewhere (kind of like how Dr. House will test for treatable diseases before a more likely but fatal one). It pays to methodical, to understand the signals being transmitted, and working backwords to see where the connection goes wrong.

Doug, can I take you up on your offer for terminals? I'd also need to borrow your crimper, mine doesn't do 0.100".

I have a few terminal pins if you need any. I will be at Doug's on Sunday.

Quoted from Sparky

I have a few terminal pins if you need any. I will be at Doug's on Sunday.

Thanks, Doug will check to see if he has them tonight. If he doesn't have, I'll take you up on that.

Victory lap (hippochrome is playing and gabbing, like usual, it's how he plays):

Man, and I thought I never shut up...

Congrats man!  Your patience and hard work (and great info from the regulars) really paid off!

That'd be your other left Hippo.  Lane save is on the right  

Congrats!