UPDATE- This problem mysteriously resolved itself once. It started acting up again 8/16.

I got my first pin, Space Invaders, several weeks ago. After replacing some bulbs and fuses it is (was) fully working. Now I have this weird problem.

My thumper bumpers and slingshots seem to effect one another and I cannot figure out what changed or went wrong. Here's a rundown of all the problems that popped up at the exact same time.

-Left bumper triggers right bumper and left slingshot, but not itself.
-Lower bumper completely dead.
-Right bumper triggers self as it should.
-Left slingshot triggers self, but also triggered by left bumper.
-Right slingshot doesn't trigger at all, but it still scores.
-My right drop target doesn't reset.
-My ball kickout doesn't kickout anymore.

All the above symptoms appeared at the same time. Everything worked fine one night and went bad the next time I turned the game on.

So far I checked all the voltages on the rectifier board and they are good. I've also looked for obvious crossed wires and found none.

I'd appreciate any help you guys can give this pinball newbie. Thanks!

Scott
OKC, OK

Bump for the day shift

I did reseat those and no luck. I also did the coil test. The kickout, right slingshot and lower bumper don't fire during the test. The right bumper fires when the left bumper does, just like in play.

Thanks all!

I did the switch test and all switches are good (well the clone chamber showed bad but that's because I forgot to remove the captive ball first and it hits the switch when the PF is elevated).

Clearly there is something, perhaps just one thing, that is causing the problem because all the symptoms appeared simultaneously. I doubt 3-4 resistors or diodes or coils went bad at the exact time, but what to I know.

I'll check the offending diodes with my ohm meter. Can I do the with them still soldered in place? I need a refresher on how to test the caps if someone can help me there. How do I test the coils, I have no idea there.

I do have the manual already, but thanks for the link.

Back to the switch matrix. Here's the other 1/2 of that page of the manual.

// Error: Image 114875 not found //

It shows the columns and rows. Looks to me like all of my trouble solenoids are in the same column. But that's the switches it shows, not the solenoid wiring. That column looks to be labeled 31 and says A4J2-5. Problem is I don't know what to do with that info. Do I chase it to a wiring or connector diagram or does it point me towards something on the MPU?

Now to mix it up a little more I want to show a potentially bad chip on my board, my U1. Pins 12 and 20 are clearly buggered and all are well tarnished. The chip below in U2 isn't socketed or buggered and only slightly tarnished on the legs.

// Error: Image 114876 not found // // Error: Image 114877 not found //

Here another shot of my manual shows the pinouts of U1. It might even show what they do, pin 12 is a ground and pin 20 I have no idea. So again I don't really know what to do with this info.

// Error: Image 114878 not found //

I did go to pinwiki and found a reference there that says a bad capacitor on a solenoid can let it fire randomly. I do have some extra caps so I plan to replace them on the three thumper bumpers to start with. As to my next step, I'm not sure.

I appreciate any help!

_{Post edited by sed6 : Fixed the pics}

Dupe post...

What's a SCANBE? Where do I get it and the chip?

Quick update. I replaced the caps on all three bumpers. No change.

I also manually tested each coil, connecting the transistor to ground. They all fired. Most fired normally. However the left thumper activated itself and the right one. The right one activated itself and the center.

Where do I go from here?

I took a few hour break and joined the guys at Slingshots for some stress relief. Sorry we missed you! See you next Sat though.

One of the guys suggested any short would be in the wiring after the transistor. Makes sense unless something's bad on the solenoid driver board.

Speaking of which, I'm about to pull it and give it a through inspection. But I did notice a toasty cap in the bottom corner. Here's a pic.

I'm off to chase wires. Wish me luck!

image.jpg

I replaced that cooked looking cap at Q18 with one robbed from Q1, and unused one. No change.

I also reflowed a lot of the solder joints on the back of the board. No change.

I read on another thread that the constant flexing of the pins can cause cracks. I should have thought to have reflows those as well. I'll do that and then try to mess with the boogered chip.

Thanks for the info. I'm glad I didn't mess with U1.

I've gone into test mode and the solenoids behave the same incorrect way. The problems I have during play I also have with the test.

I did however these each one manually, three different ways. Grounding the coil, grounding the pin on the wire harness when removed for the board and grounding the transistor. In all cases each solenoid worked properly.

I also tested the transistors and diodes on the board and all specked properly according to the Bally repair guide.

I reflowed the solder joints for the connectors on the driver board and cleaned the pins with an emery board (a temp fix I know), neither helped.

I'm 99% sure I've eliminated a problem on the PF. Next I need to check the output from the driver board to each solenoid. I need to check the volts on the misfiring ones to see if the board is sending out a signal to more than one pin. Then if so, why?

I did check chip CA3081 on the driver board, the so called pre-driver transistor pack. Again the guide gives a voltage spec of .1v for each leg of the chip I'm testing. My test shows 1.0v. But I'm don't think that's it because only a few of my solenoids are acting wacky.

I'm starting to lean toward a problem on the MPU. Anyone know what additional steps I can take?

Great info, thanks! I'll try those tomorrow night, I just couldn't get to it today.

Okay just reflowed the connectors at J4 on both the MPU and the driver board. For giggles I checked the continuity between neighboring pins to rule out a short and also checked continuity between the pins and their first component on the board. Both checked out and none of it did anything to correct the problem of one thumper triggering another or a slingshot.

Next I'll try to reseat U11. I didn't do it at the chip at the same time cause I want to really isolate this problem...

Okay, edit. I reseated U11 and it didn't help either. I did notice that after I reflowed the MPU and hooked it back up that the led on the MPU went on solid green. I pressed the reset button several times and it went out. I then turned the game on and off and it did all 7 flashes and went back to its normal 1/2 broken state. I've done this a time or two in the past now that I recall. Is this normal or indicative of some problem I might not have identified?

Any other ideas anyone?

I'm not familiar with that part. Is it a chip? Can I test it or do I just replace it?

Cool. Pinwiki shows how to test it with a DMM set to diode mode, but the test seems limited in its results. For best results it recommends removing the chip (desoldering) for perfectly accurate results.

I can't find a source for that chip. Anyone have a link? Since it seems I have to remove it to test it, I might as well just replace it for a few dollars. Plus I don't know of I should or need to invest in a logic probe?

Okay, tested LS154 and it looks fine. I used the DDM method found here.

http://www.pinwiki.com/wiki/index.php?title=General#Testing_an_integrated_circuit

Any ideas what I can do next?

I pulled my main board today and reflowed all the connector pins. I also touched up a few suspend joints. No help.

My main board does have some acid damage. See anything that could be causing my problems?

image.jpg image.jpg

Wow, can't believe two weeks has passed. I'm kinda bummed about the solution still eluding me. Here's where I'm at; my bumpers don't all fire correctly, some don't fire and some fire others. My single drop target doesn't reset and my ball kickout doesn't kick the ball out. I've checked all the wiring, checked the transistors and resistors on the solenoid board, reflowed all the connectors on the MPU and SB and reseated all the chips on both boards. All signs point to a problem on one of those boards, but I don't know which. I just bought a logic probe, but I'm not sure what to check, next, with it. Any ideas?

I have though found some time to work on a few other things. I've purchased lighted buttons I plan on installing soon plus a bunch of LED's from Cointaker. I ordered a mix of colors and bulb types. After lots of fun with different bulb combos on the PF and backbox I decided I like their premium frosted non-ghosting. I still have to narrow down what colors go where but narrowing down the type will certainly save me some money (maybe if the ones I like weren't some of their most expensive that is. I'm gonna need over 100 bulbs between the PF, backbox and infinity mirror bulbs. Here a preview.

image.jpg image.jpg image.jpg

Look at the difference a little magic eraser makes on the yellow and orange! I've got a lot of work ahead of me. But I've got to get her fully running, any help is appreciated!

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Bumpity bump for the weekday crowd. There's got to be a few people on here that know how to help. Please

She's alive!

I came home after a long day at work and turned her on with the flick of the switch. (See where I could have gone with that?) Anyway I entered into the solenoid test mode to perform Andrews suggested tests and voila, all the noids fired! And fired and fired, then missed. Shit back to my problem it seemed.

I hadn't touched a thing before or after so something made it not work again. Perhaps time (just seconds) or temp (maybe). So I attempted to replicate my actions. Literally the only thing I did was open the coin door and backbox. So I closed them both and fired her back up and she worked again! So maybe something in one of the doors? Nope, I continued the noid test and opened closed the doors and nothing changed, it still worked.

I'm going back to play and I'll post more soon.

So I played a dozen games and it works fine so far. What sux is I don't know what was wrong. And of course this problem could pop up again. I have aspirations of really restoring this game and I'd hate to put the time and energy into that knowing this problem can pop up again in the future. Here's a short vid of the solenoids working properly. Sorry for the poor quality.

I too think its time to repin some of my connectors. Male and female. I'll also start probing around on the MPU and see now if I can recreate the problem. A push here or tug there might reveal something.

I played another dozen games this AM and am really enjoying it! I e identified a few other things I want to sort out like a sluggish bumper and slightly slow upper flipper. It's those little things I can focus on now that its running properly. I do though have 3 PF lights out that I can't resolve. That will need attention soon.

I did actually replace one of the SCR's for a bad light. It didn't fix the problem. Any ideas what to look at next?

I will pull the lamp board and go over it more closely. The lamp will light off its neighbor but I don't know that I've chased it to the board. I'll do that first.

Agreed 100%! I do want to find the source of the problem and I'll check my solder connections and diodes too. Problem is now that is running all I want to do is play it! I had a buddy come over to tonight and he hasn't played pins in years but he beat me about 5/10 games. Sheeze.

So it happened again. Same symptoms. With one addition, if you hold the button the left lower flipper now bounces back and forth and won't stay up. I was soldering underneath and shorted a GI light socket to one of my flipper wires. Any idea what I did there?

So back to my main problem. I used my new logic probe and checked pins 20-23 of U2 on the SD. 20-22 went high then low depending on what solenoid was firing. Pin 23 stayed high I believe. It blinked off a time or two during the noid test, but never lit the low light. Per Andrews direction I then tested continuity from U11 on the MPU to U2 on the SD. They all check fine with no breaks in continuity. Here's a pic of my notes. Any tips from here?

image.jpg

Fanatic mentioned a ground problem which reminds me of something I forgot to mention. When I was adjusting the leaf switch gaps on my flippers with the game turned on, I could feel the voltage when I touched the leaf switch with my allen tool (cut with a slot to adjust blades) in one hand and my other hand on the metal side rail. When I removed my hand from the side rail the current went away. Is this normal? Doesn't seem like it should be.

I do appreciate the input guys! I swapped U11 and U10 and the problem resolved itself. Again. For now. It was probably a result of reseating the chips more than swapping them I guess. I will continue to hunt for suspect solder connections. Right now I'm off to find a fix for the bouncing flipper. Here's a vid of my LEDs so far.