Tim's Rescue 911 thread

[Menace]

Tim,

Most likely not the coil. I'm not at my PC right now to type lots, but don't order a new coil yet. Too many other tests to do first.

D

 

[tim.sanderson]

Cool. I'm off work at 4pm today, so I can dig into it a little deeper then.

Thanks Doug.

Tim

 

[Menace]

OK, not sure if gtb is the same as wpc, but if the coin door is open in test the coil power is cut off. Run the test again and close the door just to make sure.

If the coil still isn't working, put the game into attract mode and test for voltage at each lug of the coil to ground. Dmm on DC volts, black lead on any ground in the game and red on each lug should net you at least 50v. If you are missing a voltage on one of the two lugs then there is a break in the coil winding. If there is no voltage at all, there is a break somewhere between the coil and the driver PCB, so look for busted wires, bad connectors, cold solder on the header etc. (This is where the manual will pay dividends)

If there is voltage and on both lugs, then it could be a bad FET or the pre-driver, and your manual ans schematic will be essential. You can take a test lead with alligator clips, attach one to ground and briefly touch the NON-BANDED coil lug and it should fire. This would verify its likely a bad FET or pre-driver. You can then test from the FET using the same test wire, one end clipped to ground then momentarity touch the metal tab of the FET and the coil will fire and this will ensure everying from the driver PCB to the coil is good, but you'll need the manual to verify what FET controls that coil.

Report back your findings and we can go from there.

D

 

[tim.sanderson]

Thanks for the instructional, Doug! I'd never have known to do that.

So, I tested the coil, I got voltage on one lug, but not the other.


Is this a repairable thing?

 

[Menace]

It means there is a break in the coil winding somewhere. Tug on each strand and see if you can pull one of them away from the lug. As log as the break is close to the lug, its repairable, just unwind it one turn, sand off the coating and resolder t to the lug.

D

 

[spiroagnew]

The second instance in the last 24 hours where the coil was actually the problem!

 

[tim.sanderson]

FIXED! Thanks, Doug!
Here was the culprit:

 

[tim.sanderson]

I've been playing for most of the evening, but a strange problem has developed. I lose all bumpers and slingshots for extended periods of time. Nothing triggers them. Sometimes they stop working during play, then a few minutes later they start to work again. (I think even during the same ball) When I do a self test, all of them work. I likely won't be working on it until tomorrow after work, but I'd love to hear thoughts on what might cause that.

Tim

**EDIT** Hmm, I fired it up one more time before bed and it seems to be worse now. It no longer seems to be intermittent. However, for realz this time, I'm going to bed!

 

[tim.sanderson]

I did a little poking around on it before work, even though the actual sling shots and kickers can be triggered via the self test menu, I realized that the switches to activate them are not registering when I trigger them by hand. I'll double check the fuses later, but I think I may need to wait until I get my hands on the manual before I get this one figured out. The good news is I should have the manual by tomorrow. (thanks again J!)

 

[tim.sanderson]

Checked all the fuses with a DMM, but everything seems swell. For the record, these are the switches in question:

 

[Menace]

Ya, this isn't an issue you want to be having... especially where it's intermittent could be tricky to track down. Without over-thinking the issue too much, I'm going to say hopefully all of these switches in the game are all on the same row or column (you will need your manual to confirm this), and if that is the case start looking for bad header / connectors on these wires in the switch matrix, then check the matrix headers for bad pins and cold / broken solder joints. Where these work / don't work, it's not likely a bad PCB component (like matrix IC's) but something with a flakey connection somewhere. (the trick is locating it!)

D

 

[frolic]

This is the same issue on my TOM. I still haven't made the time to trace the wires.

 

[tim.sanderson]

It's definitely not intermittent anymore. I've done a little looking around the underside of the playfield today, but there's not much I can do until I have the manual. I may try to trace the switch wires to see where they go.

When I read SWITCH MATRIX, is that a single physical place underneath the PF I should look for, or is it more of a network of switches, wires and boards? (I put my money on the latter)

 

[Menace]

Once you get your manual you will understand better, but the switch matrix is an 8x8 "grid" of switches that is found in most late model games. Physically it is part of the PCB set in the head (usually on the MPU).

D

 

[mwong168]

I stumbled across this link from another thread, might be a good read if the switch matrix is new to you

http://www.pinballnews.com/learn/matrix.html

 

[bstock]

I stumbled across this link from another thread, might be a good read if the switch matrix is new to you

http://www.pinballnews.com/learn/matrix.html

Excellent link! Thank you!

 

[slacker]

Tim has the Manual now I gave it to him tonight, that being said I'm sure he is going to be asking lots more questions so the Vet's might want to sharpen their pencils. Good luck man and don't rip it up in frustration you have lots of good help here!
J..

 

[Menace]

The best advice I can give anyone when working on stuff like this is don't over think it.

D

 

[tim.sanderson]

FIXED! It's amazing how simple this fix was once I had the manual.

I just had to locate the connector with the name of the row printed on it. (in this case IA17P1) I unplugged it, then reconnected it. I fired up the machine and everything works again.

 

[slacker]

FIXED! It's amazing how simple this fix was once I had the manual

Sweet then it was worth the money I paid for it! LOL
Good to hear it's back up and running.
Cheers
J..

P.S I take cash only! :lol: