Monday, May 9, 2016

Things break

When you're dealing with pinball machines, you have to know they are complicated mechanical and electronic devices and things can suddenly just break down.

When you have only one or two games that are in good condition you probably are not really aware of this, but when you have a dozen or more machines, usually one of them has an issue. Sometimes it's as small as a switch that needs adjustment, nothing really broken, but they all require work. And things can suddenly break down.

Yesterday I was reminded again of this. I had played my BK2K on saturday and everything worked fine. Sunday afternoon I switch it on again and during gameplay I notice the magna-save magnet always grabbed the pinball. The magnet was just locked on all the time.
I immediately shut down the machine. Luckily I noticed quite fast during the game that the coil was locked on and the magnet can be on for a while, it was hot but not starting to burn. Regular coils (like used in slingshots) can start to smoke quite fast (give it a minute or so..)

Anyway, time to do some troubleshooting, take the manual with schematics to see what transistor drives that coil (Q14), did some measurements with my dmm to confirm (yes - it wasn't completely shorted but the readings were off compared to the other transistors. Switched on my soldering iron, put a new TIP102 transistor in, and half an hour later the game was in complete working condition again.

Luckily that was all it took, and I had all parts so I didn't have to order anything.
It was a quick fix. But a reminder that it's not because something worked yesterday, it'll still work when you turn on the machine today..