Hi all, I have a Williams Firepower 2 that I have a switch column (column 1, credit button, tilts, coin slots) that is not responding. I have done some searching on the forum and have seen that there is a way to test to see if the problem is in the wiring or in the cpu by removing all connections and using a jumper from the pin connection on the board to to somewhere else on the board. If a switch fires from the jumper than the problem is in the wiring, otherwise its in the board? Can someone go into some more detail on how to do this? Are these tested in the switch test mode (can you run switch test mode with nothing connected to the board I'm guessing no?)? Please and thank you, it looks like there might be 2 resistors on this section of the board that are burnt and I am looking for an easy test.

If it is the board, is this worth having someone fix (I can solder big stuff but I'm not comfortable working on a board) or just buying a new modern board?

Thanks!

Thanks for the link, this looks like a great start. I don't know Mike, this is my first pin an I've only had it a few weeks. I'm only half electro savvy, took some EE courses in college so I know how to read a circuit diagram and use a mm but that's about all I remember.

Progress! The problem is not in the board, all switches triggered normally with the jumper, which is a sigh of relief that my board isn't screwed, but a bigger problem since now I have to find the bad connection in the wiring. Since it is column1 that is not working, the connection that is bad is one of the green ones at the 8 switches in this column, right? It looks like most (maybe all) of them have 2 green wires connected to each other, is there a method to test each point for continuity (work my way down from the board)? Am I correct in assuming that a bad solder at one of these switches is the most likely problem?

Thanks!

So try an measure resistance between the first female socket in the harness that connects to the board and the connection at the first switch?

Okay, all 8 connections all showed around 60-80 ohm resistance to the wire at the bracket connecting to the board. So my problem is right at the connection to the board? I can't comment to the condition of the female connection within the bracket, the tip of my mm was too big so I tested on the end of the wire sticking out the top of the bracket. Is there a way to test this bracket connection?

Thanks again!

Tested the connection to the board by pulling bracket out 1/4" and testing continuity at the post and everything tested the same. I'm out of ideas now, board is ok, connections are all ok, whole column still doesn't work.

Scratching my head... Any more ideas?

Wouldn't bad connections in that harness show up when I check them at the board?

Since I can see that the row is being received at the pin on the board, is it possible that there is something "wrong" with the connection it's seeing?

I apologize, I was reading the mm wrong. The connection from the board to each point is not reading 60-80 ohms, the connections are reading 0.3-0.4 ohms. Close enought to zero I'm assuming to be a direct short?

Thats a lot of questions, I'll try to answer in order.

No, I don't have a dmm that beeps, I'm just using the 200 ohm setting to measure continuity. Do I need to get a new dmm, or is a resistance measurement <.5 ohms good enough?

I tested the switches at the board by removing both the group and column wire harnesses from the board, and them testing with a jump wire and a diode from each of the column pins to each of the row pins. I was able to trigger every switch in the switch test.

I tested the resistance of the column 1 wire (the column not working) from the board connection to each of the 8 switches and each showed 0.3-0.4 ohms.

I'm having trouble following you after that step. Try to trigger the board through the switch?

Ok I think I get it, use a jumper to connect the wires at each switch. I assume I should use a new diode as well in each test. I do not believe this machine has a switch edge test, just a switch test. Are they different?

I just take the balls out before I do a switch test (let's be honest the pin hasn't worked for a week and hasn't had balls in it for the same amount of time). Are switches that are normally down the only advantage to an edge test? I had heard it was an effective way to troubleshoot the ground?

Ok I think I have a short? I'm trying jumpers at the first switch and both the green and white will test good for continuity but connecting them through a diode will not trigger the switch test (but removing them both from the switch and doing a quick connection will). What is the best way to troubleshoot a short like this?

Please try an keep things simple, I'm a bit close to the edge of my understanding as it is....

Thanks...Bax