My 94 VF-1 has a problem with the Tool 1 switch and the tool orientation switch in the tool changer. With the wires unplugged from both switches, on the diagnostics screen they both show a 1 (contacted). With the wires plugged in they still show a 1 even if they arent contacted. Both the shuttle in and out switches work fine, showing a 0 when not contacted and a 1 when contacted. But if i unplug the cannon plug on the side of the cabinet all four switches show a 1 under diagnostics screen. I just replaced the board with a brand new one and it still has the same problem. Im thinking maybe a ground short somewhere but i have no idea how to check that. I finally called to get a service tech in to fix it, but im just puzzled.
This problem caused a major crash which dropped the tool changer to the bottom of the machine. The machine was grabbing the wrong tool once in awhile when changing tools, untill it finally just went bonkers and had a crash. I caught it in the act of grabbing the wrong tool one time. It was changing from tool 1 to 5, and it grabbed tool 3 and just kept on running. It had no way of knowing it had the wrong tool unless it was told to go to tool 1 and then it would know its count was wrong and give up an alarm.
Any ideas, or bets on what the problem turns out to be?
Sorry for the long post, just trying to be specific.

The '94 machines have mechanical microswitches. It sounds like the micrcoswitch which counts the carousel positions is hanging up so it miscounts.

I had a door interlock microswitch hang up and a good sharp rap with a plastic hammer released it and it has worked fine since.

I think you need new switches installed; I wouldn't do the hammer trick on the toolchanger.

i have seen where the spanner or bear hug nut on the bottom of the geneva wheel shaft comes loose this drops the geneva wheel lower and the tool one dog does not hit the limit switch on tool one. how did the carousel fall down did the cheesy 5/16 bolt that holds up the tool changer break?

The bolts that hold the tool changer did break and drop the changer. But if they hadnt broke something else would have broke, maybe causing some serios damage. I got lucky, not a thing was bent or broke except the bolts holding the changer.
The problem is not the micro switches. If you read my post again, i stated that the diagnostics shows they are contacted all the time. Even when the wires are unplugged from the switches. So it cant be the switches.

Please forgive me for asking stupid question.
What if status on the switch is 1 when the switch is open.
Have you tried to close to switch and see if it does change to 0?

The switches read 0 when they are open. I know this for a fact, and also the carousel in and out switches read 0 when they are open and 1 when they are closed the same as the other two switches. I can remove the TC motor plate and both switches, then push on the switches manually and the numbers on the diagnostics will not change from a 1. I can also remove the wires connecting the switches and they will still show a 1. Before all the trouble, the switches worked by pressing on them manually and the diagnostics numbers would change from 0 to 1 when they were contacted. The carousel in and out switches work fine, its just the two switches that are for orientation and tool 1. We have three Haas VF mills ranging in model years from 94 to 98, all of them show a 0 when the switches are open.
I know it sounds crazy, thats why im stumped. And thats why i assumed the board had to be the problem. Im thinking it must be a ground short or something. Its obviously an electrical problem.

OK, problem solved.
Turns out that when you disconnect the wires from any of the switches they go to a 1, not a 0 as i thought. The problem was a jumper wire on the new board that i did not install when i put the new board in. The newer board has a lot of updates that my old board didnt have. It was a bad board after all. When the switches arent contacted they show a 0, unless the wire is disconnected.
I did not check the switches by hand after installing the new board, if i had i would have noticed that they were working now and the problem was elsewhere. I just assumed that since they still showed contacted when the wires were unplugged i still had the same problem.
Anyway, i feel a little smarter and a little dumber but at least we are now machining parts again.