SM flipper blowing fuse under rapid test load

[Monkeyboypaul]

Hello wise people,

I've recently rebuilt all 3 flippers on my SpiderMan, using the correct parts & the bottom 2 flippers are fine.

However, when changing the top right flipper coil sleeve it was really tight getting it out and a new one in there, as if the coil itself has warped the plastic bobbin thing it's attached to.

Now when i test that flipper, as in press test upper flipper rapidly in the service menu, the fuse keeps blowing after about 10-20 rapid flips.

Should i be looking to replace the coil now, or is there something i'm missing?

It's a 3A Slow blow.
The flipper movement feels smooth - nothing obviously wrong.
The solder joints to the coil lugs are good.
Correct coil.
EOS registers nicely.

It never blew before, but then that upper right flipper mech was fairly worn...

Nasty:

 

[ronsplooter]

Check the resistance on the upper flipper coil and compare to the bottom 2 assuming that they're all the same rated coil

 

[astyy]

^^^+1 for suspect coil especially if sleeve is tight. I had similar on a mech where once the coil warmed up when rapidly exercised it shorted and blew the fuse. This threw me for a while as it measured good when cold.

 

[Monkeyboypaul]

Check the resistance on the upper flipper coil and compare to the bottom 2 assuming that they're all the same rated coil

Upper is about 3ohms, vs 5ohms on the bottom 2 (with game powered off).

They're all 22-1080 coils, as specified in the manual.

Would this difference in resistance cause such an issue?

 

[Monkeyboypaul]

^^^+1 for suspect coil especially if sleeve is tight. I had similar on a mech where once the coil warmed up when rapidly exercised it shorted and blew the fuse. This threw me for a while as it measured good when cold.

just odd that it's been working fine for this long!

 

[ronsplooter]

Would this difference in resistance cause such an issue?

Not sure, but less resistance means more juice flowing across it which along with the gunning the flippers might be enough to blow the fuse. The fact that you've got 3 of the same coil and one measures a different resistance to the other two would make me think about getting a new one as there's something not quite right with it

 

[Monkeyboypaul]

Not sure, but less resistance means more juice flowing across it which along with the gunning the flippers might be enough to blow the fuse. The fact that you've got 3 of the same coil and one measures a different resistance to the other two would make me think about getting a new one as there's something not quite right with it

All true! Tend not to keep coils as spares, so will have to order one.
EDIT: Pinball Heaven has stock - ordered.