SM flipper problem

The lower left flipper on my friends spiderman gave up. When you push the button you get no flips. So, we replaced the 22NE10L at Q15 and the flipper works. Now there’s a problem with hold power. Whenever you flip the right you can see the left pulse and whenever you push down on the left and the EOS closes it pulses again. You can just push the flipper down when its in the up position though. The only other thing I checked was the diode and that looks good. Any ideas?

Forgot another thing we tried. We swapped the lower left and right coils to see if it was a coil and same problem with the lower left. Also this whole fiasco began with a blown fuse.

So I thought I’d put another transistor in just because he bought spares. Same problem. He ended up pulling the through holes on two contacts but everything tones out and I scraped off the trace protective stuff and bridged the trace to the legs of the transistors. No joy. We swapped my twd board and its fine so def on his driver board. That board is 500 bucks :frowning:

SAM flippers will work fine with no EOS switch. Couldn’t hurt to try taping over the EOS switch contacts to see if that makes any difference. Also wouldn’t hurt to check the flipper button switches. Check the wiring, especially on the double stacked right side, and check the contacts. If they’re cross hatch switches (contacts make an X when closed), look for.a missing hatch (contact). Last resort, as always, is a factory reset.

I had pitted contacts on the cross hatch switches on my LOTR that I blame for numerous flipper symptoms (weak, jitter, intermittent drops) over the years. Replaced transistors, and coils and never saw any improvement but when I replaced those switches flipper feel improved tremendously and all the intermittent problems disappeared.

Cross hatch switches? Not sure what that is.

Had to look it up. The flipper leaf switches I guess? I’m not sure how that explains why the board swap made his left flipper work and that problem came back as soon as we switched back to the original board though. Maybe I can jump the switch closed with a test lead to rule out the switch?

Missed the part about swapping boards. If another board completely corrects the problem, the issue is on the board. If the right flippers are mostly working correctly, that would seem to indicate that the power side is okay. That leaves the ground side, which the transistor is part of.

Usually when a transistor goes bad, the flipper locks on. If a new transistor partially fixed your problem (no flipper at all), you may have had issues on your driver board before you replaced the transistor. If you can follow the schematics, follow the path of the ground side on the driver board all the way back to the connector where it goes to the coil. U4 to J9. Look for damaged traces or solder splashes. If you don’t find anything obvious, you can also test the diode and the resistor in the Q15 circuit, although you may have to lift one leg to test them.

If you’re not comfortable doing board work, send it out to one of the board guys.

I have a feeling we might have to send it out anyway. New boards are like $500! Anyone you would recommend?

Ron Anthony is an awesome board tech. Email him first though as he’s on the road a lot. This board is likely one he’d prefer to work on at home.

Yeah, sorry…I also missed the bit about the board swap fixing it. Did you replace/reflow the connector in question?

Sounds similar to issues I was just having with POTC (no hold power, flipper could be pushed down with my hand). Ended up replacing both transistors, and solved the problem. But, it required jumper wires for all six legs of the two transistors. I’d just double check that everything buzzes correctly. You can use the adjacent transistors as a guide to help. One of the legs needs to be buzzed in two different places…at the diode, and at the header pin.

No didn’t think of trying that. Thanks!

I was only buzzing board traces that I could see connected to the transistor. Ill take a look thanks!

Each jumper also has one leg that goes to ground. The place it’s supposed to be soldered to for the ground is right near it, but instead of buzzing at that spot, I’d pick another spot to check that it goes to ground…like the big exposed metal area where the screw holes are for the entire board. (Because it’s possible the trace is burned up between the nearby connection point and the actual ground).

So IIRC, one leg needs to be ground (check with far away ground for the whole board), one needs to buzz with the nearby diode and the connector header pin, and I can’t remember where the third goes. (But again, all of the adjacent transistors can be used as guides…they all follow a similar pattern for their connection points).

TL;DR check that each leg buzzes with the appropriate nearby connection point, but also follow where it should go to next, and make sure that it buzzes correctly to that next spot down the line.

Yea I buzzed that point to the ground of several other transistors. Buzz to the diode is good. I think the other one is a fine board trace that goes to cap, resistor are eventually leading back to the 74HC273 “Octal D-type flip-flop with reset; positive-edge trigger” whatever the hell that means…

I’m a repair noob so take these comments with a grain of salt. Ive read that when you replace a transistor on the driver board you should always replace the associated diode. Ive also read diodes can test good but be bad.

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Good point. I’ve heard this too, but haven’t had to do it yet (though only replaced 4 or so transistors).

Yea I have some lying around and someone else mentioned that to me as well. I’m going to continue shotgunning parts and jumper wires until this stupid thing works!

Transistors usually lock on (short) when they go bad. On Stern’s, a fuse typically blows before there is any damage to the rest of the circuit. Because you haven’t blown any fuses, I suspect the diode and resistor are fine. More likely related to the replaced transistor. It’s very easy to pull a pad when replacing one, which could easily cause the symptoms you’re seeing. Not enough solder could also cause those symptoms. You need to see solder from both sides of the board on all three legs.

If you can, take close up pics of the new transistor (both sides) and post them here.

The flipper fuse was blown. Before we got a new fuse in its place he replaced the transistor.