What's new
Pinball info

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Night Moves Sticking Pop Bumper

Biff

Site Supporter
10 Years
Joined
Jul 21, 2011
Messages
1,253
Location
Near Grantham
Hi

Both pop bumpers sometimes stick down when activated, probably 1 in 5 times. If you touch the bumper metal lightly the bumper will return to normal rest position. I stripped one down and the plunger is fine, I ground down the edge slightly anyway. I also stretched the spring a little as well. It slides fine in and out of the sleeve. Put it all back together and it still does it.

Maybe a leaking transistor. I made it stick then power down the machine. The bumper still stayed down. Could it be residual magnetism? Anything else i can try? I can see nothing binding.

Anything thoughts

Cheers

JB
 
I do not know how Gottlieb poppers work.

But my scared stiff had a similar problem. The pop bumper bracket was bent, and not perpendicular to the playfield. So the solenoid was powerful enough to bring the ring down, but the spring did not have the oomph to return it.

Magnetised coil stop ?
Magnetised coil plunger ?

Just test by seeing if a screwdriver sticks to them

You also get a really irritating problem in williams games where the damage/ wear/ pitting on metal surfaces that smash together causes them to bind every now and then. The upkicker bell plungers do this. I have cured this one by either replacing the offending items or by sanding out the pitting on both metal surfaces with a dremel and / or wet and dry

Failing that, burn the sodding thing. Hateful machine. I got a crap score on it. It is designed to hurt your back when moving or playing it
 
Cheers

It does not retain magnetism, a slight push makes it release. Also if you push the bumper down manually, it does not stick. So was thinking it was residual elctro magnetic rather than permanently magnetised. I will double check to see how sticky they are though.
 
I'd say it's micro particle bonding. Strip and rub impact surfaces with fine emery.
 
Back
Top Bottom