Pinball Restoration

Restoration or Reconstruction?

In the previous page I described how my father and I made a lucky startin pinball restoration when we managed to get a much-abused Spanish Eyes working after just one night's tinkering.

The electronic machines were a little more tricky. Included in our bulk purchase of six "dead" machines were two examples of Flash, a Tri Zone and a Time Warp. We had a look at Flash first as, having two machines, we thought we would stand a better chance, trying to build one complete machine from the two.
One machine had a badly damaged backflash. As described in the previous page the Fire Brigade had entered the box with hatchets. This had not improved its appearance and the glass had been smashed in the process. This machine had, also, a badly damaged playfield. It had been scrawled on with marker pens and much of the design was almost hidden under years of accumulated grime, congealed fag ash and stale beer.

We decided to put the whole of this machine on the back burner -- if not on the back incinerator! We set up the other Flash and had a look underneath the playfield. The first sight of it did not raise our hopes any more than the other Flash had done. There was almost as much insulating tape as wire and loose ends were swinging in the breeze, or would have been if my living room had been draughty.

Trying to trace the wiring was made rather difficult as the same colour had been used everywhere to replace broken or burnt out wiring. Whoever had wired the playfield must have had to be scraped off his ceiling by his wife! In the end, marker pen additions or no, we had to use the playfield from the first machine. Once we were satisfied that we weren't going to be burned to a crisp we plugged in and switched on.

Now, we had been led to believe that fault diagnosis on electronic machines was much easier than on electro-mechanicals because the score displays show which component needs attention. That's the theory. We weren't sure what you should do when none of the displays light up...

There was power getting to the displays as, with the backflash glass off we could see a faint orange glow from each display unit. The test meter told us that the correct voltage was coming from the power board but several test points on the main Central Processing Unit (CPU) board were showing a low voltage reading.

The only trouble was that we had no idea why they were showing a low voltage reading. It's a bit like a novice trying to mend a car by following a manual. The manual starts by saying things like ``remove the cylinder head'' without saying how! We shrugged a lot and played on Spanish Eyes a bit more and finally took Flash to bits and set up Tri Zone.
As the electro-mechanicals had done, it gave out a fair amount of musty smell and a small but significant amount of bluish cotton wool seemed to be growing on the inside of the cabinet. This was carefully cleaned off and the wiring checked for similar traces of mould and fungus. It was, thankfully, absent.
This machine's wiring was in a better state than Flash. There were a few swingers but it was obvious where they had come from and they were quickly soldered or joined with screw-in joining strips. I have never liked twisting wires together and strapping insulating tape round them and it's a bad habit to get into.

Tri Zone lit up nicely, apart from (again) the score displays. It was dead (of course!) and showed the same low voltages on the CPU board as Flash had done. We tried asking a few people in the local arcades. What a lot of ignorance there is about pinballs! Most arcades called in outside help to fix their pins when they went wrong and most left them until there were enough problem machines to warrant paying call-out charges. So now you know why there are so many weak flippers and broken machines in seaside arcades. Most arcade mechanics don't even know how to alter the pricing of games!

Finally we left Tri Zone switched on for a full weekend and the next time we turned it off and back on the displays lit up. The machines were damp, remember? Computer boards such as CPUs and driver boards do not like damp. But several scores of little bulbs not only lit up the backflash but also built up a fair amount of heat behind the glass -- and dried out the boards!

There were still plenty of problems. The drop targets dropped but refused to reset until the next ball. Taking one to bits showed us the reason -- someone had oiled them to make them drop more easily! Under the back of drop targets is a horseshoe-shaped piece of copper with two contacts which brush against contacts attached to the back of the target as it drops. One scores the target score and the other registers the fact that the target is down. When all the targets are down they are pushed back up by solenoids.

The oil was stopping the contacts from passing current. Furthermore one of the horseshoe contacts was broken. The horseshoe is made of copper but the contact is a silver-coloured metal dome, rivetted to it. One of these was missing. They look like a big blob of solder, so that is what we replaced it with. It may not last as long as the proper part but it will be just as easily replaced the next time it falls off.

I've no doubt the purists will be smiting their brows at this stage, but these machines will never win best machine awards. We bought them to play and only realised along the way what fun could be had by tinkering and fettling! By this time we were answering phone calls to each other by announcing ``Bispham Flippers!'' Other callers just got confused. Readers will have assumed by now that we are not called Burke for nothing...

The backflash of Tri Zone showed that a one, two, three and four player game was being played, all at the same time. When certain lights on the playfield were lit in sequence one or more of the player lights on the backflash would either light up when they shouldn't or, if they were lit already, would suddenly become much brighter and burn out.

This was caused by a problem on the driver board and was solved temporarily by swapping the board for one from another machine. On switching on again we failed to notice that one of the pop bumpers had pulled down and was being held down, as the solenoid was continually being powered by the new driver board. We noticed something was wrong when smoke started to curl round the playfield under the glass.

On switching off we heard the bumper pop back up and by following the wiring diagrams deduced that there was a faulty transistor on the replacement driver board. A new transistor was soldered in and the game was playable once again, with no ill effects (not even a cough) from the smoking.

Tri Zone was working. But I had now found a Gorgar in the backyard of the firm where we had bought the other machines. The cabinet held several inches of rainwater and the playfield had been stood too close to a paint sprayer at some time in its history. Would we be able to secure and restore? All will be revealed in the next thrilling instalment...