Thursday, November 26, 2009

new articles

Posted a lot of new articles the past weeks.


How to fix a sag in a playfield. This was posted on rgp so I asked the person if I could write an article about it.. sometimes playfields are warped and it's really no fun playing a pinball game like this.. so you can make a whole fixture to make the wood flat again.


Dutch Pinball Open competition 2009. It's been a few years since we visited the competition (or another event organised by the dutch pinball organisation) but it was really nice seeing a lot of people again and meeting new people.



The yearly Rock around the Jukebox show in Rosmalen. Every year this show is held in Rosmalen, the Netherlands. It's their biggest jukebox show. A lot of pictures are online..



Merlins Magic: a custom, handmade pinball machine by Henk De Jager.
If you're interested in electro-mechanical pinball machines, in custom made pinball machines, game design, .. you really have to see this.
It's a unique game, with some special features, it was fun to play.

Tuesday, August 25, 2009

Medieval Madness repair from hell

A friend asked for help with his Medieval Madness game.. suddenly the left popper (which returns the ball from inside the moat) activated about 10 times when the game was switched on.
I told him it would be the opto that was bad, so at startup the game thinks there's a pinball laying in the moat and tries a few times to kick it out. After about 10 times the machine decides there's a problem (either with coil or opto) and gives up. During gameplay the ball isn't kicked out until the game starts a ball search.
He had already bought a new opto pair and connected it in place, with the same result.

Weird.. I'd think the opto transmittor is burnt (which is usually the problem) so replacing both the emittor and receiver should solve it. When I got there last week I noticed one of the wires going to the connector where the optos plug in was loose. A few drops of solder fixed it, wire made contact again with the pin. Measured with my dmm to verify there was voltage. Checked continity from the pin to where it comes from on the 10-opto board, everything ok.
Measured all pins and voltages on this 4-pin connector, everything was present. So the other wires were also good.

We traced the wires back to the opto board, measured continuity. Everything was good.
But in switch test the left popper opto never worked. It's switch nr 26 btw if I recall correct - I don't have schematics here so could be wrong in the switch numbers. Tested some other switches and optos, they worked fine.

Put in the new opto pair, didn't work. Connected it into another position, there it did work. So the opto emittor and received were fine.
Checked with a digital camera, the emittor gave light. Lit with a flashlight in the receiver - didn't register in switch test. It did when the opto pair was connected in another opto position. So the opto was definitely good.

Checked what pins on the 10-opto board were used for this switch, followed traces on the board, measured some resistors and diodes.. didn't find anything wrong.
Didn't want to spend more time troubleshooting the board (didn't have a manual with schematics) so took the 10-opto board home to test it in my MM. Only way to be sure the board was ok.

In my Medieval Madness pinball machine it worked fine, the left popper opto registered. I did notice capacitor C1 was missing on this opto board.. but it worked fine in my game so probably wasn't really necessary.

The MM cpu was also brought to my home this weekend. Tested it in my game, it worked fine, all optos and switches registered like the should.
So the cpu board also didn't have any problems. No problems with LM339 ic's whatsoever. The problem had to be in the playfield wiring of that machine and not in the boards. A good thing because I didn't want to start replacing components on boards..

So yesterday evening I went back to this MM to further troubleshoot the opto problem.
Put all the boards back in. Measured voltages on optos themselves - got 12 volt, when optos were aligned it dropped to around 1 volt. So the opto did get its voltages and worked but somehow the cpu did not register this.
Again measured continuity to make sure there were no broken wires between the optos and 10-opto boad.

Looked at the switch matrix and tested all switches around this switch 26. So 16, 36, 25 and 27 (top left lane, left inlane, right troll, ball through 4, castle entry opto).
All worked fine. So this indicated there are no wire breaks and correct diodes on the other switches ?

Tested with unplugging the opto and plugging it back in. Suddenly the game registered the opto ?! So somehow it did work.. Yes it works !! Problem solved ???
Turned the game off, switched it on again, go into switch test.. nothing ?!
Damn.. it's broken again.

OK so we somehow have an intermittent contact ?? As it suddenly worked and then stopped again.
Measured continuity on all the connectors and wiring (again).
Wiggled with the connectors to see if it suddenly made contact. Nothing.
Checked on the board if there were somehow broken traces. All looked fine.

Then I remembered the missing capacitor C1 on the opto board. Maybe, just maybe, this would filter out something and make the signal for this one opto just a little bit stronger ? You never know ??
I know it's a weird theory as the board worked fine in my game and other optos should also have the same problem but you never know.

At this point I really had no options left.. couldn't think of many possibilities.
Did a factory reset, even completely remove the batteries.. as it could be a phantom problem.. game thinks at startup the opto is bad and goes in a diagnostic mode and just ignores the switch (even if later it starts to work again). Seen it happen before in my Whitewater when a closed switch was ignored forever by the game..

Factory reset doesn't bring a solution. I now start just guessing what it can be and testing things over and over again.

Tested again with the other opto. Moat enter opto (switch 31) registered fine all the time.
Switch 27 is the castle enty opto which is the next opto in the same column. Maybe there was a problem with this column ?

Back into the switch tests. Drawbridge test (to lower the bridge as the game always puts the bridge in the high position when you switch on the machine), lower bridge, test opto 27 castle entrance.
Works fine. Test opto 26, left popper.. hey suddenly it works ?!

We may have found breakthrough here.. Opto 26 works after opto 27 is activated once ???
Maybe there's a problem with this capacitor missing on the board and one opto needs to be activated before the other one will work ?? (very weird theory but after spending too many hours looking at playfield wiring I start to believe anything you tell me)

We test further.. switch game off, game on, opto 26 doesn't work, bridge down, opto 27 works, opto 26 now also works.
What's going on here ???

Bridge goes up again and opto 26 doesn't work anymore. Hey, wait.. that's really weird. So the problem is not related to opto 27 but with the position of the bridge ??

Ok the motor of the drawbridge also works on 12v, it's even the same grey-yellow wire that goes towards the optos. Maybe the 12v is incorrect (and this C1 smoothing capacitor filters out a ripple caused by the motor ?) Measure voltages for the motor is activated, see nothing special.

Back into the switch test. Test again: bridge up: opto doesn't work. Bridge down: opto 26 works. Test again and again. Same results. OK now we can reproduce the problem we can really look for the source of it.

I put the bridge in a halfway position, go into the switch test.. manually activate both microswitches that register the position of the drawbridge.
Up position: microswitch works fine.
Down position: microswitch works fine. But what do I see on the dmd in the switch test ? Opto 26 disappears when this opto (number 46 btw so same row but 2 columns further down the line) is activated ?!?!?!?!?!?!


Test again, and yes.. somehow if microswitch 46 is activated, opto 26 just disappears from the switch matrix.

I check the wiring on this microswitch as there's has been soldered on it and notice it.. the white wire is in an incorrect position !
There are 3 legs on a microswitch, one has the white wire and the non-banded end of the diode, middle has a green wire, 3rd has the banded side of the diode. I check with other microswitches and the white wire is incorrect, the correct sequence of microswitches is: non-banded end of diode (nearest to the pivot point of the metal arm), green wire, and 3rd pin has both the white wire and banded side of the diode.

The owner tells me that diode once was loose, the bridge didn't move at all anymore, and someone (who knows something about electronics but nothing about pinball repair) soldered it back into place.. Seems this person did solder the diode correct but not the white wire !

I solder the white wire in its correct position and now everything works fine.. YES YES YES !

I'm very glad to have solved this problem.. but it took me about 6 hours in total to solve it. Aaaaaaaaaaaaaaaaargh.. all that lost time just because 1 little wire was not in a correct place because someone who didn't know a thing about pinball machines thought he could do a repair..

Weird thing is that microswitch 46 itself worked fine (so the game never indicated an error with it) and the other switches around it in the switch matrix also worked fine.

With switch matrix problems and diode problems I always expect the problem to be with a switch directly in the next/previous column or row. So with switch 26 the problem can be also with a diode of switch 16, 36, 25 or 27.. but not with a column even further away ?

And the other stupid thing that made us lose a lot of time is that this microswitch 46 is totally hidden below the playfield (it's part of the drawbridge assembly) and the game always immediately raises the bridge when switched on (and thus activating microswitch 46). It's not a switch you immediately test when you're in the switch test (and it already shows as active so why should you test it manually again ?)
as you have to go in the drawbridge test to lower the bridge..

Friday, August 7, 2009

New website update

Updated the site a bit this week. Most significant change is the new layout of the main page. I added some pictures and put more links to subcategories - before these were hidden on the 'pinball articles' page.

Also updated a lot of old articles with new, larger sized pictures.

When I first started my website (many years ago) it was designed to be able to accomodate browsers in 640x480 resolution. I doubt many people still use this, but the result was that a lot of old pages still had pictures that had become very small on todays high resolution screens.

So I dived back into my archive of pictures (you don't want to know how many gigabytes I've collected over the years) and put high-res versions online on many articles. Hope you like it all..

Wednesday, July 29, 2009

CHECK FUSES F101 AND F109, J127 AND OPTO 12V SUPPLY

This was the error message I got monday evening on my Attack From Mars pinball (AFM) machine. The left flipper didn't stay in the up position, so I had soldered in a new flipper coil. The old coil tested bad with my dmm, probably the small wire had broken somewhere internally.

Anyway I played a testgame now the flippers worked again.
Suddenly the game got confused, strobe multiball suddenly started when it shouldn't, and the game kept firing out pinballs.
Something definitely was wrong here.

I turned off the pinball machine and when I switched it on again I got this error on the dmd: CHECK FUSES F101 AND F109, J127 AND OPTO 12V SUPPLY

Ouch. That's bad. The weirdest thing was that I couldn't get past this error, the test buttons at the inside of the coin door just didn't work at all ?!
That's worse.. because I couldn't get into the diagnostics and selftests and see what else the game said was wrong or what was working.


I opened the backbox, all leds were fine though. To be sure I checked all fuses. All ok.
Measured voltage on the test points, 12v regulated and unregulated were fine. So this 12v circuit was working.
J127 was also still connected like it should be, hadn't become loose or anything. Also checked all other connectors (if I'm not mistaken J140 also is needed for the 12v circuit).

Looking at the underside of the playfield I noticed the led on the opto board was still lit. All connectors were still in their place.

Further troubleshooting. The error message means the games computer thinks the 12v power supply is broken because it suddenly can't see any opto switch anymore. These switches are more than the 12v voltage itself. There's also an opto board
at the bottom of the playfield involved, and the switch matrix itself.

I disconnected the wires on the opto board, tested again, plugged in the connectors, tested again..

I don't know if the not working testswitches were related and default behavior ? These are outside of the switch matrix
and have their own connector on the cpu board, direct input switches.

Started to think the cpu board itself was broken.

Disconnected the switch matrix connectors, then the error message changed into 'check fuses 101 and 106'.
Testbuttons still didn't work though.

Anyway as it was getting too late I stopped troubleshooting.
Read Clays guides to refresh my memory about how the switch matrix and 12v opto board worked (hoping to find
a detail I missed that would solve the problem), searched for the specific error message..
Seems not a lot of people have gotten it, there's not a lot of information to find about it and only a few people
who had it but not how they solved it..

Yesterday evening then I continued my search.

Checked the opto board, disconnected all connectors, no difference, still the error.
Plugged them back in, problem wasn't solved.

Played around with several combinations, unplugging direct switches, unplugging switch matrix on the cpu board, .. put pinballs in trough, left them out, ..
Sometimes I got the F101, 109, J127 error, sometimes I got 'Check fuses F101 and F106'. Sometimes the game even went right into attract mode but I couldn't start a game and always still couldn't use the test switches.

As the 12v was still on the board and connectors were plugged in, I focused on the cpu board and the direct input switches. I even considered if the 'enter' testswitch had suddenly become bad and didn't make contact anymore ?

Replaced chip U20 on the cpu as this IC is socketed and easy to change. Still no difference.
I first had taken an IC of my spare parts.. but maybe there was a short in the switch matrix and this new IC would be immediately broken again ?
So I removed it from AFM and put it into my Medieval Madness pinball machine which has the same type of cpu board.

MM still worked fine.. so this U20 IC was ok.

Next step: swap cpu boards.
I removed the cpu board out of AFM and put it in MM. I did unplug the connectors that power the coils, as the AFM roms would operate incorrect coils. Didn't want to risk causing damage to my MM too :-)

Much to my surprise MM booted fine with the AFM board installed. The machine started, went into attract mode, all lamps went on, .. (it gave some errors about stuck switches which is normal as MM has some optos where AFM has regular
switches so it thinks they are stuck).
But I could use the testswitches so the direct input circuit on the AFM cpu board was ok and switch matrix was working too..

Weird. So the AFM cpu board itself was fine and the wiring should be fine too ? Only thing I could think of was a short somewhere underneath the playfield of AFM (although then fuses would have been blown ?), or a problem with the testswitches or their wiring ?

So the next things I did:
- checked the connectors at the interconnect board (but they were ok)
- checked every fuse again, removed it from the holder, measured with my dmm, put back in fuse holder
- put the cpu board back in, but I did remove the batteries so it lost its memory

Switched the game back on.. and it worked fine ?
Gave the expected 'Factory Settings Reset' error because the remote battery holder had been disconnected, but the game booted fine, testswitches worked fine, and I could play.

So this problem suddenly went away ? I have no idea what exactly solved it.

Was it a bad fuse that gave intermittent contact ? Connector that was a bit loose ?
I'm not sure. I guess the cpu somehow got into a corrupt state and removing the battery fixed it (in the past I also have had a few times a weird error that spontaniously went away after a factory reset).

I don't really like this kind of problem. If something is broken, I want to find the source and solve it.
It problems suddenly solve themselves, you're not sure what caused it, and what's more important: you're not really sure it is completely solved and will not come back in the future..

I'm glad it's solved so fast.. still spending too much time troubleshooting problems on my Black Hole pinball machine :-(

Wednesday, July 1, 2009

Flooded Fire

We bought another game this week.. this time it's a special project.

It's a Williams Fire. Problem with it is that it's been in a flooded basement.
The water came just up to the bottom of the backbox.
The playfield is covered with mud, some assemblies are rusted, ..
It doesn't look very good, but the electronics are still fine, so probably this game will still power up without any problem.. The playfield itself is totally covered with mylar so the paint and artwork doesn't look to have had any water damage. Most damage is to the assemblies at the bottom of the playfield which need a very thorough cleaning. But as some people take coils and wire looms into a shower to clean them, these parts can be cleaned without any bad long-term effects.

We're not sure yet if we'll clean and restore the game or just part it out..
it'll be a lot of work..

Pictures are posted on facebook, search for the page of www.flippers.be
You really have to see the pictures to get an idea how bad it looks..