The Addams Family Pinball

As you know (if you’ve been reading through this blog) I’ve had problems with the decals which I applied to my machine, meaning that for all screws which go directly into the cabinet, I’m having to cut away the underlying decal to stop it from “squashing”.

Famous for causing problems with all decals (not just sub-standard ones, which I appear to have) is the area behind the leg mountings. This area comes under varying amounts of pressure during its lifetime, due to the way pinball machines are played, which decals don’t like. As a result the decals crease in next to no time around the leg mounts. This is also apparent in WPC factory cabinets where decals were used for the first time (most Monster Bash machines for example).

Investigating on line, a solution appears to be, to make a cut in the decal around the leg mount. Well this is what I would have be planning to do anyway (and to remove the cut away part instead of just leaving it on the cabinet – as with the screws).

But then I found the new STERN leg mounting plates. I’m guessing that as STERN is using decals now 100% on its newest machines, they’ve had to find a solution to this problem. And I think they just have. The solution appears to be a touch of genius.

It consists of a metal angle plate which fits between the leg and the cabinet. This plate keeps the leg away from the cabinet (and therefore the decal). The plate itself is screwed to the cabinet, thereby preventing any movement and stopping the decals from creasing.

So I purchased a couple of sets to try.

Attaching them was quite straight forward – fitting them onto each corner with the screw provided; cutting away the decal underneath around the edge of the bracket; removing the bracket again in order to remove the decal from underneath and then re-attaching the bracket.

Mounting the legs onto the cabinet was then pretty straight forward and once they were fitted and tightened, each leg was distanced about half a millimeter from the cabinet thereby preserving the cabinet decal…

…or so I thought….

Back to the mysterious flipper firing together with the lamps, when all the lamps were on and flashing.

My first guess was that there must be some kind of cross talk on the power board and so was just about to check the circuit diagrams to see how on earth that could be happening, when I thought I’d first check to see if the problem also happened when the left flipper switch wasn’t connected. It didn’t. So could there also be some sort of cross talk with the switch wiring, somehow? Then I discovered something very curious…

The interrupter for the opto flipper board was slightly misaligned to the opto switch, this made the flipper switch very sensitive. On aligning the interrupter with the switch manually, the flipper no longer activated together with the lamps. So it would appear that the current drain from all the lamps being on at once affected the threshold of the opto-switch ever so slightly, so that it then switched, because it was near to its switching threshold anyway (due to the receiver receiving light from the transmitter even when it was supposed to be off) thereby firing the flipper bat.

Unfortunately trying to physically bend the interrupter into shape didn’t work. In the end I switched the left and right opto boards and the problem was solved.

Job done.

I received the jet bumper spring from a local shop today and fit it into the weak jet bumper. It didn’t work. I took it out again and compared it to the one that had been in there originally – it was the same (a 10-135). Time to order the right one – again!

I had been doing a bit of research into springs, as you do, and discovered that the strength of a spring is proportional to the thickness of the wire and inversely proportional to the coil diameter and the number of turns in the coil. So, as I now have to wait until I receive the right coil, I thought I’d do a little experimenting. So I took a turn out of the coil:

I put this coil in the pop bumper, but it also didn’t work! Guess I’ll have to wait for the right spring after all!

Well I got the playfield and all the boards connected up today – it all seemed to make sense actually, which was a good feeling and I discovered in the process, that I had actually incorrectly marked up two of the female plugs! I also managed to plug J105 onto J106 by mistake and in trying to take it off again, broke two retainers off of the male part on the PCB (which I had so carefully soldered onto the board), so I just left it on there. It turns out that I will be needing to plug J105 onto J106 for the “black-out” mod anyway, so that’s another reason why it can stay on there for now (both connectors are connected in parallel to one another).

I attached the outlet cable into the back of the machine, the loudspeaker panel and then (very nervously) switched the machine on.

The GI lighting came on and a message kept repeating in the display, in French. There was no smell of smoke.

So I turned the machine off, turned the “country” dip-switches 7 and 8 on the CPU board to “off” and switched the machine back on agian. The GI lights came on and the message came up in English. Something about the book keeping numbers being reset, or something. Not a surprise really, as I had already taken the batteries out of the CPU before cleaining it and connecting it in to the machine.

So I went into the test menu and tested everything I could test and everything passed with flying colours – apart from two small issues:

1) the metal ring of the lower jet bumper would not return to the upper position once activated. At first I thought the coil was permanently on and panicked, switching the machine off. I then remembered that as I was putting the jet bumpers together, one of the bumpers had a spring in it, which was notably weaker than the other two. I made a mental note at the time. This weaker spring was in this lower jet bumper. So I switched the machine back on, went through the test menu again until I got to the lower jet and put it into test mode. As the metal ring was drawn down I applied a little pressure to lift it again and once the coil had deactivated, sure enough, the ring popped back up. So I obviously needed the right spring.

Now according to numerous shops, there are two “suitable” springs for the pop-bumper a 10-326 and a 10-135. However, looking into it a bit deeper, the 10-326 is used in the pop-bumpers only and the 10-135 almost everywhere else (for WPC machines). I suspect I have a 10-135 in the pop-bumper and require a 10-326.

Incidentally, why the metal ring doesn’t return even with the weaker sping is something I find peculiar: when the coil de-activates the ring stays down; by applying a slight pressure under the ring it then pops up again. But then trying to get the ring to stay down again manually is impossible, with the spring returning the ring to the upper position every time! So I’m guessing that when the coil activates it draws the plunger down until the plunger hits the end-stop. When the current is removed from the coil so that the magnetic field collapses, there must be a residual magnetism in the plunger and coil stop which holds them together. As soon as this bond is broken however, the residual magnetism dissapears. Sounds plausible. The spring therefore needs to overcome this force of attraction and that caused by the weight of the ring. If it is unable to do this, the ring stays down until broken manually. Solution: stronger spring (I verified this by temporarily using two 10-135 springs instead of just one – thereby doubling the return force, which worked).

2) The second problem was also interesting: in testing the lamps in “all lamps+flasher” test the left flipper bat activated in time with the strobing lamps. It also activated with the strobing lamps in the “all lamps” test. But I couldn’t get it to activate in the “single lamp” test or the “column/row lamp” test. Also activating the flipper using the flipper button didn’t light up any lamp(s). I’ll investigate this one later….

So I put the clean (repaired) boards into the backbox today and also put the playfield back in. A milestone in my renovation to say the least!

Oh and look there, I’ve also received and mounted the START button!

It would have been my Dad’s 89th Birthday today. Happy Birthday Dad and RIP.

Back to pinball….

I cleaned up the PC boards today and having cleaned the Power Board, noticed that J106 (the GI lamp plug) had been burnt on two pins

So one minor repair later, I was ready to go….

So I fixed up the lamp loom (having replaced all of the lamps) and attached the coil/flasher cable to each of the coils*, cleaned up the playfield hinges and supports and attached them and voila – playfield DONE!!!!

* I had decided a few months back, that it would be much easier when putting everything together, to firstly cut the coils from the coil cable loom, put a plug and socket on each of the coils/coil loom cables, mount the coils into their associated mechanics and then mounting each individual unit, complete with coils, onto the playfield, than to try to juggle a cable with coils hanging off it. It proved to be quite easy in the end.

To make things easier with the cabling, I separated the cable harness into its three individual looms: the lamp loom, the switch loom and the coil/flasher loom. I had intended to start with the lamp loom first, but then remembered (?) I had bought an “mod” for my AFM.
From www.pinballcenter.eu I had bought some LED backlighting for the green MARTIAN targets. I wanted to hook this backlighting up to the individual MARTIAN letters on the playfield, so that when the targets were in play and the corresponding MARTIAN letter lit, the actual target would also be lit. Hitting the target extinguishes the associated lamp, and would therefore turn the backlighting for that target off – a cool effect in theory.

In order to connect these target backlights up to the associated MARTIAN lamps, I needed to make some minor modifications to two of the lamp boards.

Having fixed the backlighting to each of the targets, getting them into position was unfortunately harder than it should have been, as the cabling from the backlight meant it was a tight squeeze for the target plus backlighting in the allotted slot. With some minor adjustments however, I managed to get them all in.

Whether it will all hold together in play, or even look good, is something we’ll have to see. Needless to say that this mod is reversible, meaning I can take everything off again, should it be necessary.

Having got back from skiing it was back to the playfield and finishing off the mechanics on the back of the playfield (including the cable loom holders), excluding the playfield supports, as I’ll be putting these on last.

Next – the cable looms…

The past couple of weeks have been spent cleaning and polishing the playfield mechanics and mounting them onto the playfield.

Rebuilding the pop-bumpers wasn’t as bad as I thought it might have been – the most difficult part actually being aligning the needle in the centre of the cup and adjusting the switch gap, so that the switch always activated in the “live” area of the pop bumpers. As the cups had been worn some-what in their own “active area”, I swapped the switches around so that the worn areas of the cups were well away from the switching area.

The rest of the mechanics then followed without a hitch:

Once completed, the playfield looked like this: