I recently purchased a Rollercoaster Tycoon and there's many things all happening wrong.

Some switches are registering randomly (the center mechanic target and the handyman target), which causes modes to just start randomly, the game sometimes kicks out extra balls for no reason, the opto sensor behind the handyman target sometimes doesn't work, as well as some other things. Additionally if the Rocket switch is ever triggered it just starts a new game immediately.

The switch matrix shows a good 10 or so switches being pressed when they shouldn't, and the rocket is registering randomly in the switch test as well.

I presume it might be something on the CPU board? I swapped out the Power Supply board with an extra working one I had to see if it was a power issue, however that didn't fix it.

Any suggestions?
Thanks!

I went to check on this for you but now the game won't boot up fully (lights come on but the DMD/start screen never comes up, never makes the startup ding), so I guess I must've messed something up when I put its regular power supply board back in

I recall them being kind of in a clump, not following any row/column pattern.

Okay so I read about power issues and it seems that R114 is the place to test to see if it has 5V. Assuming I'm doing this correctly I can only get it to read about 3V, so that would indicate a problem there. What that means and how to fix it, however, I have no idea.

Also my friend who I purchased this game from did do a check over the boards before selling it to make sure there was no acid damage.

Oh also to add to my post above, I checked all the connectors first, looked over all the fuses and I don't see any that look close to blown, but I could take them all out and test individually if necessary.

Ah, didn't know that for sure but I did test them all without removing them (just didn't know if that was correct or not), and inbetween my last post and this post I pulled and tested them all individually anyways since I had nothing better to do. All were fine both tests.

Pinwiki says to check U19 next but I've searched everywhere and can not seem to find it on the board no matter where I look. Any tips?

EDIT: Found it, the part where it said to unplug the J16 connector above helped me locate it, it's on the heat sink so it's not labeled as U19 on the board.

EDIT Again: Okay but now the real question is to try and figure out how the heck I test voltage on a metal casing like the Pinwiki says to do.

If just putting the positive end of the meter on the plate and then putting the negative end on ground somewhere is the correct way to test this, then it's only reading 0.25 V, however I have no idea if I am testing this correctly or not.

Yup that's the thing! We posted at the exact same time, but the way I was testing is indeed like you said, so if that is correct then yeah I'm only getting 0.25 V there and will start to unplug things like the article suggests to do next.

When I got the 0.25V reading I was touching the ground end to one of the nuts at the bottom of the head, perhaps that is not correct because when I touch the ground end to the metal piece behind the boards that gives me the correct 5V reading, with or without J16 plugged in. Still am getting 3V at the R114 though.

Bump!

Yeah it was Marvin's although it was having these issues all weekend at the show.

Once I get the power back up and running I'll get back to you about the CPU stuff

Power issue solved, a wire had come out of its connector.

Now as far as the main issues go, the primary issues come from switches in row 4 being joined up with switches in row 6 (as in they will always activate together). I will mark this thread as resolved and start a new one with better and more specific information in the OP to reflect what I have narrowed it down to.

Also as far as switches registering randomly goes, it's because the connector to the handyman opto board was loose, which would just cause that opto to trigger on its own if it jiggled around, and since whenever it activates it also activates the switch in row 4, that is why the boo stuff was also randomly activating. Resoldering that connection fixed that issue.

EDIT: Nevermind creating the second thread, I wrote it all out, went to add a picture of the Switch Matrix, and then when I went to switch back to the tab I accidentally clicked the X and closed it, so I lost it. Then I fixed the problem on my own. I will probably have some new questions soon, but my main issues have been solved! (I do wish I would've been able to post that thread anyways though just to document the problem for others who may run in to a similar issue)