That sounds weird. Is the switch staying snugly mounted or does it loosen when the problem starts? If so, there are products that lock the screws in or there are the little star washers that may help

Have you put in a new diode board? I had a similar problem, except it was on the diode board side of things. I had to apply pressure to the diode board itself for the outhole switch to become active when the ball drained or else it wouldn't recognize it. My traces on my diode boarf where in kinda bad shape though. Have you tried testing continuity from the switch to the diode board also?

don't smash it . send it my way.

try adding a washer plate to the screws before tightening it down. it will prevent the squishing of the switch body and stop it from becoming sticky. Also check for improper assembly. Its common to have those washer plates missing and the spacer between the metal halves are also usually missing. Know what I mean?

Ditto.

Take a break from it. Watch some skinemax, have a beer.

check your switch test when hitting the flippers. Sounds like you have a bad diode.

It's safe to say the problem is not the switch. Sometimes it's easy to get locked in on one idea and then get frustrated when it doesn't work. I'd tale the night off, then I'd start fresh tomorrow checking every switch in that row and column for shoddy wire connection, broken diodes or shorted lugs.

Sounds like you did a commendable job bringing this dog back from almost certain death. Don't let the last little gremlin boil your blood!

Take a break and then take Hawk007s advise. Sounds like shorted switch or diode shenanigans to me

Have a beer, and fap on it.

I know nothing about these games, but Halo2jak's advice seems to be worth looking into; if there's a separate board with diodes that goes with those switches, check it.

Something you said in that last post hit a nerve. You're not just touching the switch - you're lifting the playfield to get at it. Possible wiring problem? Maybe a wire broken internally that sometimes works but then doesn't when it gets moved or vibrated about?

We'll disregard all that . Congrats on the good detective work!

Damn, that is a weird fix. It's above my knowledge level, but I thought the 4004 was identical to the 4001 in every way only rated slightly higher.

Maybe one of the Gurus will chime in and enlighten us.

diodes can be bad right out of the box. They are funny that way... A 4001 is a low power 4004 . You just plain and simple had a bad diode. They will test good even .........until power is added then fail and test bad after that.

i have a feeling this issue will resurface. I've had similar issues. What they always turned out to be is a crushed switch somewhere else not even related to the switch causing problems. Something smashes the prongs and diode on a switch somewhere else, causing grounding issues and makes the switch matrix do crazy shit. or another issue I had, someone put the diode on the wrong legs somewhere else, and put the diode on backwards. That also caused crazy shit at random times.

I'd be surprised if it doesn't come back as well. I'd be looking to the prior switch in the same row/column.

Comeon have faith, I say its fixed for good!

I just read this thread and the whole time I was thinking this was a diode issue. I know how goofy these switches act when the diode is on backwards. Here he had the wrong diode on and once he put the correct one on, problem solved.

Good Luck to the OP

I'll just throw this out there... just because... maybe it'll help someone save some frustration someday

As I was reading this thread, until I got to toyguy's post, this is what I was going suggest too. That thought should never be disregarded in dealing with electronics, ever. It is an idea that most everyone would probably consider, but unfortunately that idea can be dismissed while troubleshooting, way too easily. If the problem does come back again, don't forget this idea is still a possibility also.

(kirkgun is now having flashbacks to some frustrating days of work, long ago)

Always assume the worst of wires and cables. Wires and cables sheathed in plastic are awful and terribly evil things (but don't use uninsulated wires please).

Don't ever trust a "momentary" continuity test (or any kind of "short-term" test) as an indication that wires are good when dealing with an intermittent problem. And by "short-term" test, I mean lasting weeks or months... argh...

I get what you are saying sort of, but really, issues due to wires internally breaking are some of the most rare I have come across in pinball machines. Most issues are connection issues (connectors, broken wires from lugs). Most internal wire break issues I have seen... in fact all of them that I can think of were in harnesses to moving parts such as the ringmaster head in CV, crane in LAH, and globe in JD.

Thinking it is a wire issue should be one of the last head scratcher attempts, which may be where we are here.

I wholeheartedly hope that your problem is fully solved.

I just find it funny that going with the 4001 over the 4004. That's like saying, I wasn't able to pull a 16' boat with an F-350 diesel because it was too much truck, then I hooked the boat up to a V6 F-150 and pulled the shit out of it. lol

Maybe the whole batch od 4004s was bad due to improper storage (by the supplier) or something?

In any event, congrats on the maintenance. Give us some pics to see what you've done to restore this machine.

Trace the wires of the switch and you'll probably find a break, loose wire, or shorted legs of a switch in the chain somewhere. It's a great opportunity to clean underneath the playfield and clean the subways as well.

+1

Atomicboy,

100% agreed with everything you say. Internal conductor breakage is far less common than at connection points, in any application. Moving wires/harnesses more commonly will suffer internal breakage problems than non-moving ones.

It wasn't common in the field I used to work in either. And troubleshooting them in that field was very often a pain in the butt, requiring running additional "test" cables over long streches. The relative infrequency of the problem made diagnosing that particular problem, more difficult because it way down the list of things we would consider (and there was no outward appearing reason to suspect it). It's just what you have left when your other ideas aren't working. Simply disregarding the possibility, can lead to lots of wasted time/money (and frustration of course, more frustration than anything else with just a pinball machine).

We all tend to look for the types of problems we see most often, first. And that makes sense. It did happen often enough though (often it seemed to be a manufacturing defect of the wire, not something that happened as a result of use). But, as he said above, his problems were coming and going with manipulation and movement. That's why it makes more sense to me in this case than usual.

At the point he is at it's time to check the daisy chained switches behind and after, and then I would maybe try some jumpers as well and see if that is a game changer.

Nothing in the trough preventing a ball from sitting right in there is there? Switch arm bent correctly, and isn't just at the range of activating the switch is it?

You should test the diodes you're pulling on the DMM. Maybe you'll find one out of spec and you can have some higher confidence.

Also, is the trough on space jam reed switches and not standard micro switches?

go into switch test and activate all switches one at a time until you find one that scores oddly..THEN check all switches it its associated row and column and you will find the problem. Sometimes banging on the playfield in switch test shows weirdness also. Look for multiple closures

Do you have ball trough divots causing the balls to hang up? When the balls drain and you have the issue watch the trough to see if the balls move down like they are supposed to. Also watch when the multi ball starts to see if when it kicks two out, if the last 2 don't move down.

Should have been only 1 bad....more than likely there is another problem somewhere else.....And only 1 bad diode will cause all sorts of funniness though. Also check ALL switches at the edge of the playfield. Sometimes when going up and down a switch gets pinched....

The power feeding these switches could also be bad. It is daisy chained from switch to switch .....clip your test leads on and buzz out the wires for the whole column or row while wiggling them

I just skimmed through this and I'm not sure if someone has said this or not. The top half of your CPU board is where all your switches connect. Look at what color wires are on the switch your having problems with. Take a volt meter and check the voltage at the switch. Then compare it to the voltage on that same wire at the board. They should be the same, if not your gonna be wire hunting. If they are the same it sounds like you might be having a switch matrix problem on the board.

You can do a test to isolate the playfield by removing the sw. matrix connectors and going into test mode and see if problem is still there

Yes, that could have been the issue as its on the same row as the trough switch

These things are also not necessarily wired from left to right like the chart in the manual says. They're probably the last two in the chain with the trough being on the end. I will be surprised if this does not correct it.

Wow, that sounds odd! Maybe that was it?! I'm interested to see if that fixed it...

that was it for 95% sure. by every fault you described and it usually is something that simple
Enjoy..