The Addams Family Pinball

The original pinball machine uses Insulation Displacement Connectors (IDC) for all of the connectors in the back box, which have a reputation for being unreliable – especially the ones handling the General Illumination (GI) circuits. The reason being, that these connections take a lot of current constantly and the high temperature in the backbox derates the current carrying ability of the connectors, so that the connectors (and pins) eventually burn and break.

When replacing these connectors it is therefore highly recommended to use Molex type connectors with crimp contacts to improve the reliability of the contact. However making a crimp contact requires skill and the use of a special crimping tool, both of which can be easily acquired, but for me the biggest sticking point was the need to put two wires into a single crimp contact, which, although can be done, brings more unreliability into the equation than usig a simple IDC connector.

So, even though I had already bought several Molex connectors and pins, I looked for a suitable IDC connector.

On RGP it was mentioned that ITW Pancon still makes such connectors. So, having looked on their web-site, I found a suitable source of connectors.

My intention was to firstly replace both GI connectors on the Power Board (one 11 pin and one 12 pin) and to replace the 6 pin connector to the optoboard for Thing’s motor (which had always given me problems). Interestingly, Pancon supplies connectors which operate reliably at high currents and high temperatures and so are ideal for the back-box application.

So the parts that I needed were:

• CTH156F18-12C (high power; 18AWG; 12 pin)
• CTH156F18-11C (high power; 18 AWG; 11 pin)
• CT156F22-6C (22 AWG; 6-pin)

Unfortunatlely the 11 pin and 12 pin variants weren’t readily available (requiring a minimum order quantity of 2,000 parts) but I was able to source small quantities of the 5 pin and 6 pin High Power variants which would be adequate for what I had in mind.

After a long time searching and waiting, I found and won a Magnet Burn decal on eBay:

Self adhesive magnet burn decal

It turns out it’s a genuine Bally original and came with mylar to protect the slingshots. A bargain.

As I’ve decided not to remove the mylar from my playfield, this would imply that to use this decal would require me to cut off the upper portion of the decal where the mylar starts in front of the two blue target (in front of the grave yard). This, combined with the fact that the colours on the decal didn’t match 100% to my playfield, I decided to scan in the image, colour match the colours and print it out on water slide paper to apply to the playfield.

As the decal has five colours to match, which, based on previous colour matching experiences (with the apron) would take for ever, I extracted the maximum area from this decal with the fewest colours for matching. As the magent burn is mostly visible in the white portion, I finished with the following extract, requiring just three colours to be matched (plus black):

Extract from the magnet burn decal with just 3 colours

In trying to match the three colours, I developed a new iterative technique which reduced the time in matching the colours considerably. Once I’ve made sure this technique works most of the time, I will publish the details here, of course.

Having matched the colours on my target decal paper I had to use another piece of decal paper to print out the final decal. Despite the fact that this second piece of decal paper came from the same supplier, the colours on the second sheet didn’t match the colours on the original sheet meaning I had both wasted time and a piece of very expensive water slide decal paper – ughhhhh!

Despite this set-back I thought I’d try out the decal anyway, so having sealed the decal with lacquer and letting it dry, I carefully cut out the decal with a sharp knife around the black “frame”. I then immersed it in water long enough for the decal to come away from the backing paper and then applied it to the playfield. In so doing I damaged the decal, so with this trial I learned a valuable lesson in how not to apply it when I come to applying the final version.

Playfield with Magnet Burn water-slide decal applied

To be honest,  I don’t think it looked too bad. OK, so the colours may be slightly off (especially the grey) and the edges of the decal still need to be tidied up (and painted black, as the water slide decal paper is white) but this definitely shows the potential of this method.

Having verified this methodology, I removed the decal again, leaving the magnet burn area visible again:

Playfield with magnet burn, for comparison