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Night Moves - System 80B Nightmare

lukewells

lukewells

Registered
Joined
May 1, 2012
Messages
2,377
Location
Blackpool, UK
Well, I thought it would be cool to own a tabletop pinball machine, and I was wrong.

I bought it as working, but has intermittent sound and needs a display.


So firstly, the "working" part :-

You can coin it up and start a game, all coils, lamps and flashes seem to work fine.

If you press the flipper button firmly then it works fine, as soon as you tap a flipper button quickly (like when you get a little spark on the flipper button) then the game resets

1) Disconnected the reset board - still the same

2) Replaced the diodes on the flipper coils - still the same

3) Cut all ground connectors off the transformer frame and directly mounted all the ground wires to the transformer frame through the bolt holes - still the same

4) Replace the bridge rectifier and filter capacitors for the 12v (to 5v) circuit - still the same

5) Added direct ground wires soldered onto every board and then attached to the ground strap - still the same

6) Removed the ROM daughtercard and re-soldered it all, replaced all the pins and re-soldered to the CPU board. Replaced all the sockets with new turned pin sockets - still the same

7) Re-flowed everything on the 5v power supply, put new pins on and replaced the pot with a fixed value resistor - still the same

8) Soldered wires from the +5v out of the power supply and soldered them onto both the CPU board and driver board - still the same

9) Added additional filter capacitors directly on the CPU and driver boards where the +5v sources are - still the same

10) Cleaned up all the edge connectors and re-pinned all the important connectors - still the same


Nothing has made any difference at all. What next?





So the soundboard was not intermittent - it was dead. I put it on the test bench and managed to repair it so that I could manually trigger the sounds by grounding the data lines, and that seemed to be fully working.


Put the sound board in the cab and the LED does not flash, it just either stays on or off and you get static sounds.

Put the sound board back on the bench and it it working fine.

Back in the cab still nothing.

Checked all the sound board voltages as fine.

Put the CPU board back on the bench and tested the RIOT chips using the Leon test ROM, all outputs seemed to be fine.

Checked every IC on the driver board and checked every transistors





Then there is the displays. I have a display-board (untested - but I can see the glass is good) but I get nothing out of them at all.

Checked the voltages are fine in the game.

Checked the RIOT was working, found 2 dead 74LS175 and a dead 74LS04 next to the display connector on the CPU board and replaced them all.

Re-pinned the connectors at the display and CPU board end - still nothing out of the displays.

The next step will be to check for activity on all the datalines on the display board itself with the game running.


To make matters worse, working inside the tabletop is twice as hard as working in a normal pinball backbox, you have to really lean over the top to get in at the boards, everything is hard to get to, there is no slack in the wiring and everything is upside-down.

The system 80 design is a nightmare!

So after many hours of work, the only thing I have made any difference to is that I have a sound board that will work fine on the bench, and technically I have fixed all the crappy ground and power problems that Gotlieb are plagued with, but it didn't make any real difference.

Any ideas on the resets?
 
Last edited:
lukewells said:
Well, I thought it would be cool to own a tabletop pinball machine, and I was wrong.

I bought it as working, but has intermittent sound and needs a display.


So firstly, the "working" part :-

You can coin it up and start a game, all coils, lamps and flashes seem to work fine.

If you press the flipper button firmly then it works fine, as soon as you tap a flipper button quickly (like when you get a little spark on the flipper button) then the game resets

1) Disconnected the reset board - still the same

2) Replaced the diodes on the flipper coils - still the same

3) Cut all ground connectors off the transformer frame and directly mounted all the ground wires to the transformer frame through the bolt holes - still the same

4) Replace the bridge rectifier and filter capacitors for the 12v (to 5v) circuit - still the same

5) Added direct ground wires soldered onto every board and then attached to the ground strap - still the same

6) Removed the ROM daughtercard and re-soldered it all, replaced all the pins and re-soldered to the CPU board. Replaced all the sockets with new turned pin sockets - still the same

7) Re-flowed everything on the 5v power supply, put new pins on and replaced the pot with a fixed value resistor - still the same

8) Soldered wires from the +5v out of the power supply and soldered them onto both the CPU board and driver board - still the same

9) Added additional filter capacitors directly on the CPU and driver boards where the +5v sources are - still the same

10) Cleaned up all the edge connectors and re-pinned all the important connectors - still the same


Nothing has made any difference at all. What next?





So the soundboard was not intermittent - it was dead. I put it on the test bench and managed to repair it so that I could manually trigger the sounds by grounding the data lines, and that seemed to be fully working.


Put the sound board in the cab and the LED does not flash, it just either stays on or off and you get static sounds.

Put the sound board back on the bench and it it working fine.

Back in the cab still nothing.

Checked all the sound board voltages as fine.

Put the CPU board back on the bench and tested the RIOT chips using the Leon test ROM, all outputs seemed to be fine.

Checked every IC on the driver board and checked every transistors





Then there is the displays. I have a display-board (untested - but I can see the glass is good) but I get nothing out of them at all.

Checked the voltages are fine in the game.

Checked the RIOT was working, found 2 dead 74LS175 and a dead 74LS04 next to the display connector on the CPU board and replaced them all.

Re-pinned the connectors at the display and CPU board end - still nothing out of the displays.

The next step will be to check for activity on all the datalines on the display board itself with the game running.


To make matters worse, working inside the tabletop is twice as hard as working in a normal pinball backbox, you have to really lean over the top to get in at the boards, everything is hard to get to, there is no slack in the wiring and everything is upside-down.

The system 80 design is a nightmare!

So after many hours of work, the only thing I have made any difference to is that I have a sound board that will work fine on the bench, and technically I have fixed all the crappy ground and power problems that Gotlieb are plagued with, but it didn't make any real difference.

Any ideas on the resets?
Click to expand...


Being as I am presuming the 5volt is nice steady dc:),I would bell out the PITA daughterboard ,being as ya prob have a rom burner so redo them,and I know RIOTS can be weird sometimes

Welcome to the lovely world of gottlieb Sys 80:rofl:
 
TYHO said:
Being as I am presuming the 5volt is nice steady dc:),I would bell out the PITA daughterboard ,being as ya prob have a rom burner so redo them,and I know RIOTS can be weird sometimes

Welcome to the lovely world of gottlieb Sys 80:rofl:
Click to expand...

5v measures 4.992 at the CPU and I get a min and max of 4.989 and 4.993 during gameplay

AC ripple is 2.1mv measured at the CPU board and stays the same


I just tried several times and it is totally repeatable....

Press the flippers really firmly and you can complete the game with no resets.

Tap the flipper button quickly, so you see a spark on the button contacts and the game resets instantly (no reset board attached!)

It's repeatable all the time.

I just tried replacing the flipper diode on the left yet again, just incase the last one was duff and nope, left flipper still causes a reset.

ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff Gottlieb



Also as per my first post, the daughterboard has been removed, new socket fitted, new pins fitted and it is rock solid. EPROM's have already been re-burnt.
 
So Gottlieb create the reset board to stop games from locking up and burning out coils etc, because the System 80 CPU board does not have a watchdog circuit.

If the board does not have a watchdog circuit then what the f*** is resetting it when the flipper button is pressed? (as I have the reset board disconnected)
 
So I was staring at schematics at 2am and eventually noticed that the reset signal for the sound board has to travel through the display PCB (because why not? After all nothing has to make sense with Gottlieb electronics) so I might be able to get sound working tonight.

To try and get to the bottom of the resetting issue I am going to dissable the POR circuit and fit a manual high/low toggle switch on a flylead to boot up the CPU. I am also going to add a pulse stretching circuit and a reset LED to the CPU board, so that if something pulses the reset low, even while it is tied high, then I will know about it.

Fingers crossed!
 
A couple of ideas... should the flipper button switches have capacitors across them and if so are they missing? And disconnect the reset board (it's not needed) but leave the 40 way connector with the mod on in place.

Good luck!
 
OK so I added a pulse stretcher and an LED for the reset line.

When I sparked the coil, the reset light came on, so its the one shot circuit in the POR section that is picking up the spark and triggering.

I cut the POR and re-connected the reset board (as in theory, the reset board will just kick the reset after a few milliseconds of no IRQ activity) and guess what...... the reset board doesn't reset grrrrrrrrrr

So CPU board is back on the bench and while the reset section does not look terrible, it has some very very old corrosion which is making the solder impossible to melt, so its getting a bit messy pulling out the corroded components. I'm going to bin most of the POR and fit a reset IC instead, and then jumper the board as required

This time next year Rodeny, we'll be playing Night Moves
 
You know when you guys organise these dinner and talk things at the pinball shows, with some pinball celebrity. Could someone please arrange to fly the Gottlieb engineers over?

I would love to talk to them about how much crack they were smoking when they designed their boards. :rofl: It's almost as though the people that worked on them had no previous experience or electronic background whatsoever. Best practices are completely ignored (ground planes? onboard watchdog timer? filtering and noise suppression?, driver protection? oh and god damn card edge connectors everywhere), the wires run needlessly all over the place (resetting the sound board from the display WTF?) Even their transistor selection .... all non-standard and end of life parts. (except the 3055 maybe)
 
Gottlieb were great recyclers!!!! Oh we haven't had time to design that"fook it throw a random coil on that " that in 30 years will be as rare as hens teeth!!!!!
 
I'd love to, but the pinball cabin has drained away all my money. If I don't fix this board then I will put my name down for a new one, but that'll have to wait a couple of months, got a huge shopping list of parts I need already to get all these machines 100%
 
I know what you mean Luke. Thought I'd buy a couple of odds and sods for my upcoming Taxi refurb. £140 later !!!!!
 
Who actually counts? I wrote a spreadsheet for TAF at the beginning and realised it would damage my relationship if it was ever found. If asked, "it cost £20 and that was cheap because they usually cost £75".
 
OK as per a previous post, I have now binned all the components from the POR circuit and fitted a random power watchdog IC that I had in stock instead.

The game now boots reliably and can be played without it resetting!!!

Still got to fix the sound and display problem
 
upload_2014-3-28_19-9-4.png
from pinrepair

glad you now have it working - if ya need to try owt on mine,feel free to bring it round
 
TYHO said:
View attachment 6352
from pinrepair

glad you now have it working - if ya need to try owt on mine,feel free to bring it round
Click to expand...

Cheers Chris,

I kind of did similar to what you just posted above, although I didn't have those instructions, so I just looked at the schematics and cut everythng off that looked pointless. Probably got 25-30 components cut off now. Oh and I don't have any of those Dallas reset chips, but had something similar which was a power watchdog by Microchip.

It didn't work on my first attempt as the Microchip IC was open-drain, so after scoping it out I realised that I needed to add an extra pull-up resistor and now it's working great
 
lukewells said:
errrr my Mrs thinks I have about 10 pinball machines:rofl:
Click to expand...

Got to be the blag of the century ! A case of not seeing the wood for the trees.... heh. Fortunately for you, she mixes them up to only count ten in her head... God help you if you ever line them all up together.
 
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