Weakened solenoids across the whole game after league meeting

[DRD]

I hosted a league meeting for the first time on Sunday. As a result my games received vastly more continuous play than ever before under my stewardship

Fathom, Paragon, Vector, Addams Family were all still playing strong after 5 hours.

But Shadow and Twilight Zone had weakened coils across the board. They were still playable, but ramp shots in particular were a little tricky. Balancing this was that the slingshots were less dangerous. This morning, both games were playing properly again

Any ideas why this might be please ? I know heat reduces conductivity. But this applied to all the games. And these two had LEDs in which ought to have helped. So I wondered if this is a power supply/ capacitor/ bridge rectifier type issue?

Thanks

 

[lukewells]

Checkout the connector pins from the transformer secondary to the power driver board, as they heat up, resistance increases. Also failing bridge rectifiers can get "leaky" when they are hot, resulting in decreased current output.

It shouldn't be so much of a problem on WPC games, but with old wiring, the copper oxidises and resistance increases, as resistance increases the wire gets hotter, and resistance increases further and further. This can be common with late 70's / early 80's games, it's easy to check by feeling the wiring from the transformer to the Power driver to see if its really hot. The GI wires will pretty much always be hot (well not so much in your case with LEDs)

 

[pinballmania]

Check the sw1 and sw2 voltage levels on the output of the flipper opto switches. At rest should be 11-12v, when pressed should be less than 1v ideally. If it's getting higher than 2v then you'll start getting unstable switching, meaning the flipper has a high power duty switching during what should be low power hold. The effect is twofold. The flip is weak as the flipptronics is seeing on/off/on/off instead of solid on. Secondly the amount of time high power is on is much longer, so coils get much hotter, increasing coil resistance, and potentially warping coil sleeves. Coil resistance increases by 10% for each 20degree rise in temp. (Very approx). So hot coil = higher resistance = lower current= less power.

 

[DRD]

Thanks Andy

I checked these. All the rest voltages when games playing were 11.4 to 11.5. When the flipper buttons were pressed, all were below 0.9, with one outlier. The outlier was sw2 when pressed on tz left flipper and this was 1.2

Will get in touch as I need a few bits across my machines

 

[mufcmufc]

Maybe having 8 machines on at once caused a slight voltage drop and thus reduced the power getting to them?