Wild Fyre Feature Lights Flicker

Ok, we at least know the valid power detection / reset circuitry on the MPU board is not the problem.

And yeah, for whatever stupid reason TP1 and TP2 are opposite between Bally and Stern lamp driver boards

Something smells of these two problems being related to interrupt requests to/at the CPU. You've already changed the two PIA chips and the CPU which play a big part in this circuit. Until you get the meter we don't know if the 555 timer and zero crossing circuit on the board are working properly.

To prepare you when the meter arrives, set it to Hz, connect the black lead to ground and probing the red lead at:
Pin 40 of U11 (Display Interrupt generator input) should measure around 320Hz +/- 5%
Pin 18 of U10 (Zero Crossing detector input) should measure bang on 120Hz

Can you do one more thing for us. Measure the voltage on pin 18 of U11 of the MPU board. Then hook up the logic probe to the MPU board and put the probe on pin 18 of U11. Does the probe indication change when the game triggers a reboot? Let us know the results.

#52 6 years ago

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oldschoolbob

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Voltage at U11 pin 18 is 0.2 MV. Logic probe indicates LO and no pulse. No change when it re-boots.

I forgot to tell you before - no I don't have a ROM programmer. Only twice have I ever needed new ROMs.

Bob

#53 6 years ago

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oldschoolbob

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I was going to pull the board to perform the tests that barakandl suggested back in post 41 but I just noticed the pins are accessible from the top. I'll test those tomorrow in the game.

Quoted from barakandl:
Another thing with the 5101, check the /OD pin for pulsing. It should be pulsing like the R/W pin. I have seen a board with a dead gate (4049 i think it is) on the OD pin of the 5101 that caused some interesting problems.

I don't see the OD pin - I did find the R/W pin (pin 20). I think the OD pin is marked OE on the NVRAM board (pin 18). Am I correct?

Thanks

Bob

#54 6 years ago

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Quench

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OP
Quoted from oldschoolbob:
Voltage at U11 pin 18 is 0.2 MV. Logic probe indicates LO and no pulse. No change when it re-boots.

That's good. It was a long bow but worth checking.

If you had a ROM programmer I probably could have made code changes to try and debug it.

You mentioned you were going to try and hook it all up on the bench to see if it still rebooted. Did you ever do this?
I can't remember, did you try running this Stern board in the 8 Ball machine?
Out of curiosity, what exactly do you measure at the 5V test point (TP5) on the MPU board?

OP
Quoted from oldschoolbob:
I don't see the OD pin - I did find the R/W pin (pin 20). I think the OD pin is marked OE on the NVRAM board (pin 18). Am I correct?

Correct, it's pin 18. Bally calls it OD on their schematics.

#55 6 years ago

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oldschoolbob

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I tried the Stern MPU in the 8 Ball last week - It re-booted just like in the Wild Fyre.

I haven't hooked it up to the bench tester yet. I got everything out ready for testing (5 Volts, 12 Volts, and 25 Volts). I should be able to get all 7 flashes on the bench. But I thought I'd try Andrews tests in the game first. Tomorrow I check the 5101 and TP5 and report back.

Amazon says my meter should be delivered tomorrow - we'll see.

Bob

#56 6 years ago

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Quench

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Yes, do Andrews tests first.

It seems to be rebooting more constantly in attract mode, is it still ok in game mode? What happens if you start a game and just leave it (not play)? Does it eventually reboot?

Are you able to get into test mode now or does it still reboot the moment you press the test button inside the coin door?

#57 6 years ago

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oldschoolbob

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It does reboot more in attract mode because I haven't tried game mode in a week. Right now I still have 8 Ball ROMs in. What would happen if I try a game with the 8 Ball ROMs in place? The Wild Fyre ROMs seem delicate (they have been repaired). I'd rather not install them until I know it's for the last time.

I haven't tried test mode either. I don't think the test button was causing the reboot. Back when I was trying test mode it was re-booting every 10 seconds so getting into test mode was difficult.

Bob

#58 6 years ago

???

pinwiz_pa

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Mifflinburg, PA

11y 23,150 127

When I get roms that are delicate I put them in sockets so the socket pins take the wear and tear from inserting and removing them.

#59 6 years ago

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oldschoolbob

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Thanks pinwiz. I never thought of that. I'll try it.

Good tip.

Bob

#60 6 years ago

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oldschoolbob

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Much to report today. Meter arrived!!!

First I checked 4514 pin 1 on the LDA = it fluctuates from 1.8 to above 2 K Hz.

Then I checked U11 - pin 40 = 316.8 Hz

Then U10 pin 18 = 119.9 Hz

Then 5101 pin 20 = Hi and pulsing

Then 5101 pin 18 = Hi and pulsing

Then voltage at TP5 = 5.23 with Radio Shack and 5.3 with Mastech

Voltage at 5101 pin 22 = 5.52 with Radio Shack and 5.61 with Mastech.

All tests done in the game.

Does anything look out of place?

Bob

#61 6 years ago

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oldschoolbob

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Quoted from barakandl:
Only problems I have with it are annoyances like slow auto ranging and the auto power off after a few minutes.

Andrew, You can turn off the auto off feature. I found this in the manual:

I thought the lights where you insert the probes would go off when you plug in the correct probe. But mine stays on.

Bob

sleep mode (resized).PNG

#62 6 years ago

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Quench

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So the Display Interrupt generator and Zero Crossing detector are presenting proper frequencies at the PIA chips.
The reading at pin 1 of the 4514 on the LDA seems high, but it's also not a simple repetitive waveform meaning it's difficult for the meter to latch onto - we can ignore it.

Pin 20 of the 5101 should indicate the opposite of pin 18. Can you verify pin 20 again - I expect it should be Lo and pulsing.

On the first page of your thread I see a whisker between pins 26 and 27 on the solder side of the top J5 connector. Click and zoom into the pics below. Please closely inspect the soldered pins on the board and make sure it isn't a solder short.

MPU J5 Connector pic 1
MPU J5 Connector pic 2

#63 6 years ago

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oldschoolbob

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How in the world did you ever find that!!!

Whenever I do any solder joint I always check my work with an 8X loupe. Even after I pulled the board I wasn't sure there was a solder bridge there. I checked it with a meter and it showed a short. I cleaned it out, re-checked continuity and installed the board. It's been setting there for over 30 minutes - never re-booted and the lights don't flicker.

I can't believe I put everyone through all this for such a dumb mistake like this.

Next I'll change back all the chips and try it again. Hopefully for the final time.

Thanks Quench.

Bob

IMG_1185 (resized).JPG

IMG_1188 (resized).JPG

IMG_1184 (resized).JPG

#64 6 years ago

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Quench

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Phew! To be honest, without the right diag tools I was kinda out of ideas (if you hadn't noticed) and decided to take a very close look over your pictures. Lucky you posted them with good detail! That's when I noticed that whisker short and I'm surprised the board even booted with those two critical timing signals being shorted.

#65 6 years ago

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oldschoolbob

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Not only surprised the board booted but it also played. It’s hard to believe but after I replaced all the headers and connectors on all the boards I re-installed them and played a few games to test it. Satisfied the game was working I was attempting to find the reason for the flickering feature lights. That’s when this whole mess started.

After dinner I put the Wild Fyre ROMs back in (I left the 8 Ball RAM, PIAs and CPU on the board). I fired up a game and it played fine. My wife and I played several games and it didn’t miss a beat. I still need to clean and adjust some switches and replace some lamps. Then I replaced the original Stern light driver board and tested it again. Still good.

Then I put the chips in the 8 Ball MPU and installed it and the 8 Ball light driver board. Tomorrow I’ll test it but it was working fine before I started swapping boards.

Quench, I’m so glad you didn’t give up. Not many people in this world are as dedicated to finding and solving this kind of problem. I really appreciate all the time and effort you have put into this. I can never thank you enough.

I also want to thank Andrew and everyone who followed us on this journey. It’s been almost 2 weeks but it has not been wasted. I have learned a few things and that’s what matters most.

Thanks

Bob

#66 6 years ago

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oldschoolbob

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Today I fired up the 8 Ball (love that game). It played fine. Then I tried the Wild Fyre and it played fine too. Next I need to replace some lamps and install new headers and connectors on the displays. But first I gotta get some more games under my belt.

At this point all is great.

Thanks again for everyone's help. This was a tough one.

Bob

#67 6 years ago

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Quench

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Great news!

BTW, in terms of the frequency meter (I still haven't receive the one I ordered), it probably would have also come in handy with the SB100 sound board we fixed in your Magic machine from some months back. TP2, TP3 and TP5 on the SB100 board are perfect locations to measure the tone generator frequencies and it might have helped us follow the audio path through to the amplifier chip to find the fault. There are scenarios where measuring frequency will be useful.

#68 6 years ago

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oldschoolbob

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https://www.circuitspecialists.com/usb-oscilloscope-hantek6022be.html?utm_source=Circuit+Specialists+Newsletter&utm_campaign=3896c0f1b8-EMAIL_CAMPAIGN_2018_01_09&utm_medium=email&utm_term=0_dd242259e3-3896c0f1b8-53079137&mc_cid=3896c0f1b8&mc_eid=78330a6d55

You are absolutely right. I think this meter and I will get along great. Besides frequency it will also measure capacitors. Neither are tests I need very often but nice to have. And I was looking to retire my old Radio Shack meter because it got paint splattered on it a while back. Still usable but the top corner of the display is a little hard to see now.

Speaking of meters I got an email today from Circuit-Specialists. They have this oscilloscope on sale.

I still don’t think I really NEED one but this has a lot going for it. It’s reasonable (58.00 delivered). It don’t take up much space on my workbench as I already have a laptop there that I use all the time. I’m thinking very seriously about ordering one. More as a toy because I have no idea how to use it.

Bob

#69 6 years ago

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Quench

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