My JD occasionally reports "check trough switch x". Usually it's switch 1-3, but sometimes others. I've replaced the trough opto boards with new repros from Great Lakes, but the problem is still there. Everything seems to work just fine, and the error comes up only once in a while and is easily reset by "touching" the switches in test mode. In test mode, all the trough switches seem to work perfectly without a glitch all the time, even when I stress the connectors a bit or tilt the game.

Another strange thing is, that when the error comes up, it usually reports error on two or three of the switches at the same time. So it's not very likely that the optos are the problem?

I haven't been able to find a way to reproduce the problem, but I have an idea that this happens mostly when one ore more balls are locked in the planet ring when the game is turned off and then turned back on at a later time. I have the Deadworld mod from Pinbits.

This isn't really a big problem, but it's bugging me a bit, as the game otherwise works very nicely.

One theory I have is that the 12V is a bit on the weak side, and that the voltage in given situations drops enough for the trough optos to be disrupted? But wouldn't the game then report errors on all trough switches? When first powering on the game, and the planet starts spinning searching for the ball, I've noticed that it starts up slowly for a couple of seconds and then speeds up to normal speed. Does the 12V circuit need to "warm up" like this if it's about to go bad?

I never get errors from other switches, but that could be because all the other opto switches are normally open?

How do I attack this problem in the best way?

Anyone?

I also have the plastic sleeve in the trough, and as mentioned brand new opto boards from GLM.

Read voltages at the test points: Roughly 15v at TP1, 12.1v at TP3, 5.01v at TP2. TP1 drops to around 14.8v when the planet runs in test mode, but should still be plenty. Seems all fine to me.

Had the same problem with the original boards, that's why I got the GLM boards... So the problem obviously lies somewhere else. The weird thing is, that I'm totally unable to make the trough optos glitch or flicker or anything. And when the error comes up, everything's still working tip top.

And I don't have any other issues with the game either, all switches and everything's working like a charm as far as I can tell.

Tempting to think that it's a bug in the deadworld mod software, but I can't remember if had these problems before installing the mod. And I'm not planning to revert it just to see if the problem goes away.

Thanks Gotpins, will definately check this out. This seems to be spot on for my problem, as I suspect it has something to do with the game losing track of a ball or two.