What's new
By:
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!

Space Invaders Pop Bumper

  • Thread starter Thread starter Wiggy
  • Start date Start date
W

Wiggy

My centre pop bumper fires a few times when the machine is switched on and going through its diagnostics and then stops. When you play a game it fires continuously without a ball going near it. I have changed the coil and made sure there is a large gap with the contacts whilst testing, but this has not cured the problem. Logic tells me this must be a PCB problem (A3?) Hope you can help.....
 
Hi, Wiggy,

Is there a capacitor connected into the switch assembly? Bally used these on bumper switches and static targets to increase the sensitivity. Try disconnecting it (either by unsoldering or cutting one of its leads) to eliminate the possibility of a failing component.
 
That's good advice from Jay. I had similar on my Gold Ball where it kept activating tilt - I clipped the cap leg to diagnose and then replaced it. In case you aren't aware they are small ceramic caps similar to below that are not polarised.

itp.nyu.edu_archive_physcomp_spring2014_uploads_caps_ceramic.jpg
 
have you done the built in switch test,I had a similar problem with mine,it tilted every time you hit the clone chamber,turned out a target switch was stuck on,fixing this cured the problem
 
The Invaders I bought from a local arcade had an occasional switch problem - sometimes it would tilt for no reason, or detect the outhole switch (resulting in bonus award > change of 'Player Up'/Advance Ball In Play/Game Over).

I eventually found that the arcade technician must've overhauled the flipper units, first doing the main ones, with their extra switches to operate the upper flippers. Then he'd done the upper ones, which also have additional normally open switches, simply to produce a 'firing' sound* as on the video game. These were originally gold-contact 'matrix' switches, with an isolating diode, but possibly due to being on automatic by that time Trevor had simply used high-current flipper contacts, with no diode. This caused a short in the switch matrix when the flippers were raised, and the problems above occurred when the 3-target drop bank was partially down; left and centre targets plus flipper caused one symptom, right and centre targets with flipper the other.

* which can be disabled using one of the option switches - what a thing to use up a switch on.
 
Last edited:
Hi All

Sorry for the delay, life and family have taken their bite out of me. Thanks for all your help, Jay was spot on, it was that pesky capacitor.
 
You must log in or register to reply here.
Back
Top Bottom