Williams System 6 Blackout Lock-on

[HHaase]

Ok, I put my last 2.5A fuse I had laying around in the game. It started up with no locked on coils, and I ran the coil test and it went through that with pretty much everything working. Overall, it's getting there.

The start button still does not work. I could not start a game with it or adjust any values in the adjustment area. I tried adding credits on the coin door, but those do not. Also, oddly, in the coil test I noticed that the coil I had wired backward is not working. Could it have been damaged from being wired wrong?

It's almost there I think.

Also, I should be the one paying you for all this help, not the other way around. Don't worry about blown fuses or anything.

I got so wrapped up in the coil problem, I forgot about the switches. Which coil was this anyway? Doubt you hurt the coil.

As to the switches. No coin switches. No start buton. Let me guess, all three tilts are dead too? Problem with column 1 somewhere. First place to look is the connector going into the driver board, 2J2, and the bottom pin on that connector.

But I'm off to sleep now, I'll start catching up with this again tomorrow afternoon.

 

[vipe155]

Hey thanks for all this. I feel bad that I've need so much help with this, and you've wasted so much time on my game.

By the way, it's the eject hole solenoid. It's the one that first burnt up and started this whole ordeal, and the one I replaced and wired backward (blowing fuses today) and now doesn't work even though it's wired correct. Maybe I need to check my solder connections.

 

[HHaase]

Going to be a busy night at work, won't be able to be too active here, but getting back to it while I can.

Do the upper drop-targets reset ok? How were you testing the solenoids anyway? Diagnostic tests or just throwing a ball into it?

Another test is possible that checks from the transistor all the way to the coil. Have a test-lead with alligator clips? Clip one end to ground somewhere in the backbox. Touch the other end to the metal tab on the transistor, it should fire the coil. If that works, the problem is on the driver board. If that doesn't work, it's somewhere between the transistor and the coil.

As to the bad switch......
First thing to check is the switch itself, make sure the wires are all still connected and test the diode.
If you don't find anything there, then back to the driver board. Jumper between 2J2 pin 9 and 2J3 pin 7, that should register the start button as being pressed.


-Hans

Edit: Oh, and don't feel bad at all. I enjoy this stuff, and it helps ME to better learn the system as well.

 

[vipe155]

Ok, so I should probably go out and get some small alligator clips to try testing these different coils/switches. I was doing the diagnostic test when I noticed it wasn't firing the replaced coil.

I did use the DMM to see if there was power at that coil, and like all the others there is power at the coil.

If the switch isn't working at the start button, that can mess with the whole row or column right?

 

[HHaase]

If the switch isn't working at the start button, that can mess with the whole row or column right?

Well, you also said the coin switches weren't working either, correct? You'll probably find all of the tilts dead too.... I suspect the whole column is dead. Jumpering the pins in the driver board narrows the problem down between the driver board or the playfield wiring.

-Hans

 

[vipe155]

Well, you also said the coin switches weren't working either, correct? You'll probably find all of the tilts dead too.... I suspect the whole column is dead. Jumpering the pins in the driver board narrows the problem down between the driver board or the playfield wiring.

-Hans

Ok, I just jumpered the non-working coils transistor to the wing nut in the backbox holding the ground strap, and it immediately blew the F2 fuse.

I was looking closer at this coil, and I realized that I put in an SG1-23-850DC when it's supposed to be an SG-23-850DC (I ordered the right one and the company sent me the wrong one without me noticing). Would this make a difference?

 

[HHaase]

Odd.... thought I did a reply here, guess it didn't take.

The SG1 vs the SG coil shouldn't make a difference, not even sure there IS a difference between the two part numbers. Same size wire, same wrap count.

Could be a short in the coil though, check the resistance across the tabs on the coil. May also be a bad diode too. Got any 1N4001's? I have a pile, can send you some if you need. They're annoying to test them, I find it easier just to replace them if I doubt the diode is good, so I bought a big roll.

-Hans

 

[vipe155]

Ok, I tested the nonworking coil and it comes up with less than 1 ohms. I compared that to other coils, which all tested above 3 ohms. I guess this one may be shorted then.

I did some switch testing also. In the diagnostic, I kept getting readings at 01, 02 and 08. I checked those and none of them were closed. I disconnected the two switch connectors on the driver board and went to jumper the pins. After I would jumper one switch, the game would show that switch number, then immediately start to show or cycle between 01, 02, or 08 (even though those are not connected at the time).

I checked the IC15/16 and IC17/18 chips. I got some weird readings on the row IC15/16 chips. Both posted a reading of around .2 on leg 1, and low readings on pin 8 and 16 on at least one of them. According to the pinball repair guides all legs but 7/14 should have readings in the .4 to .6 range.

 

[HHaase]

Coil is definitely shorted at 1ohm, that's what keeps blowing your fuses. No loss in clipping off the diode and seeing what it registers after you do that..... could be a shorted diode. If the coil still tests bad, you need a new coil. If the coil then tests good, it's a new diode you need. (Not sure if you can exchange it or not, if you can do THAT First of course).

Switches 1,2,8 are all on Column 1 of the matrix, which we already knew had a problem. Now we know it's on the driver board. Test R85 and W9 on the driver board for resistance. This area is different on a lot of schematics, so use this one that way we're on the same page when it comes to callouts for this area. You might get different numbers than what this schematic says, that's ok, what we're looking for is things that don't match up with other resistors for the other columns.
http://www.firepowerpinball.com/downloads/DriverBoard.pdf

Got a digital camera, and can get me a really good close-up photo of the driver board up near 2J2, front and back? Could be something shorted on the board, such as a really poor solder joint or something. I'd like to see that whole area around IC17/IC18 and the resistors up in that corner..... front and back.

-Hans

 

[vipe155]

I clipped off the diode and got a bunch of odd readings either around .2 or over 1. I checked the ohms on the coil then and got back 3.9 ohms like the others. By the way, one leg of the TIP120 for that coil isn't reading at .4 to .6 anymore, but instead like 1.5.

I checked R85 and W9 and compared them to the other components like it in that area. They had a very similiar or the exact same reading as the others. I checked all the resistors in that area and found nothing odd.

Here are the pictures you wanted. I didn't notice it before, but this area, especially under the ICs, isn't in the best shape.

http://i397.photobucket.com/albums/pp55/vipe155/IMG_1007.jpg
http://i397.photobucket.com/albums/pp55/vipe155/IMG_1006.jpg
http://i397.photobucket.com/albums/pp55/vipe155/IMG_1005.jpg
http://i397.photobucket.com/albums/pp55/vipe155/IMG_1004.jpg
http://i397.photobucket.com/albums/pp55/vipe155/IMG_1003.jpg
http://i397.photobucket.com/albums/pp55/vipe155/IMG_1002.jpg

 

[shardian]

When you wired the coil backwards, you blew the crap out of the coil diode. Replace that diode, and ll should be well now.

 

[HHaase]

Yep, just need a diode and the coil situation should be solved.

The switch matrix problem.... hmmmmm. Somebody has already replaced all the switch matrix chips, as well as the PIA. Thankfully the PIA is in a socket, it will make your life easier for sure. Something also got REALLY hot in that area, holy cow (probably the cause of all the re-work). Was it you that tried cleaning it with a q-tip, or was that already there? Most of that is solder rosin, cleans up fine with rubbing alcohol and a toothbrush. Q-tips leave lots of bits of floss as you can see.

Are the other PIA's in sockets? Maybe try swapping them around, see if the problem goes moves with the chip?

The other possible culprit is IC17. It almost looks like the solder is shorting between pins 1 and 2 on top, but that could just be glare in the photo. It's a shame they didn't socket these too when they got replaced.

I'll be honest, I don't know the switch matrix as well as the solenoid logic.

 

[vipe155]

I hadn't even noticed the back of that area, so I'm not sure what the little "fibers" were. I can get a cheap toothbrush today and clean that all up. To me it looked terrible, but I'm glad its just rosin. I can try switching the PIA around.

 

[vipe155]

Alright, just a little update.

I cleaned up the driver board and replaced that eject hole transistor again after all the trouble with it. I also put a new diode on that eject hole coil, and now all is well. Coil-wise it looks like things are pretty well fixed.

I'm pretty happy with myself because I figured out and fixed something else on the machine without any help . The top segment on the master display, 1st player and 2nd player display was out. I figured out which resistor controlled that, tested it and got no reading at all, and replaced it. The top segment now works.

I'm still having switch problems, of course. I don't think anything is shorting and that was probably camera glare, but you never know.

If you don't mind, I would like to switch gears a bit. I'm having trouble running the switch test and therefore seeing what switch is closed because the 4th digit ont he master display (or the 2nd digit saying what ball it is) isn't working right. Sometimes it comes on, sometimes it's blank. Sometimes, it's blank, then comes on after a couple minutes. What should I look for there?

 

[HHaase]

Displays I've barely done any work on, so I'll have to read up on it some more before I can even start to come up with any ideas. But the good thing is I don't think the glass itself is bad, which is the expensive part.

Which style master display board is it, anyway? The one with a lot of transistors? or the one with only a few chips?

-Hans

 

[vipe155]

It's the one with the chips. It's probably something wrong with IC4, and I'll check it out. It's not a huge deal, but it makes it difficult to test switches if it's not working. Sometimes it comes on, a few times it has come on after a couple of minutes.

I'm really worried about the switch issue. I have a new PIA, and sockets/chips to replace IC15 - 18 if need be. If not, then they will be extras for future problems.

 

[shardian]

Intermittent display, you should check for cold solder and reseat all of the connectors for the displays. Also take a look at the pins and headers/edge connectors to see if they are in good condition.

 

[vipe155]

Intermittent display, you should check for cold solder and reseat all of the connectors for the displays. Also take a look at the pins and headers/edge connectors to see if they are in good condition.

I unplugged everything from the master display, checked it out, and then replugged it in. When I fired up the machine after that, the digit showed up perfect. After that, it won't work again when I power the machine on.

Also, I was looking closer at the driver board tonight and noticed that the switch PIA had some corrosion stuff on it. Obviously, sometime the battery holder must have had a corrosion problem because the PIA chip had some on a few legs and the socket the PIA was in had the same problem. The battery holder was missing and desoldered from the machine when I bought this.

Needless to say, I pulled the PIA out and tried to clean it up as much as possible. I was attempting to clean the socket when a corroded contact in it just broke off. So, I am in the process of desoldering the socket. I don't know if this will change anything, but the socket had to go.

I didn't even think I would need any 40 pin sockets, so I don't have any on the way. I hate to deal with "The Shack" too much, but would this work well enough: http://www.radioshack.com/product/index.jsp?productId=2062605

 

[HHaase]

Yeah, those would work fine for you. Price isn't bad for Radio Shack either, not the normal rip-off.

Very good chance that the corroded socket was your problem.

-Hans

 

[vipe155]

Yeah, those would work fine for you. Price isn't bad for Radio Shack either, not the normal rip-off.

Very good chance that the corroded socket was your problem.

-Hans

Well, I went to RadioSuck and they are out of 40 pin IC sockets. Don't even have it in stock in their warehouse or surrounding stores. Now I don't know where I'm going to find one anytime soon.