I bought a NGG from a pinsider, and it certainly wasn't in the condition described. So, I finally got around to trying to get it cleaned and working properly.

After cleaning, replacing rubber rings and re-sleeving the all the coils I started to do diagnostics.

In the coil test, the left gofer goes up when the DMD says down, and goes down when the DMD says it should go up. The right gofer seems to operate correctly per the DMD.

Has anyone seen this before? Any suggestions as to how to start to trouble shoot.

The left gofer has never worked properly, so I don't think I screwed anything up during the cleaning process...but one never knows.

Thanks.

Robert

Opto's and switches check out in test.

The wiring seems correct, but I'll check again.

In the solenoid test, the left gofer operates opposite of what the DMD says.

Thanks.

Robert

OK...one problem solved, and another in work.

The wiring to the release solenoid and the up solenoid were reversed. So Now the left Gofer goes up and down properly. This is probably why the guy sold the game originally.

The right gofer won't go down now, it did yesterday when I started the troubleshooting.

I took the wiring from the left gofer release coil and jumped it to the right release coil and no joy. I then replaced the right release coil and still no joy, with either the left or right release coil wiring attached.

The right gofer coil hums a little (in pulses), but doesn't move. the coil is getting 72 v and that drops a few volts when the coil is pulsed...essentially the same as the left assembly.

By hand the left and right release coil mech's seem to have about the same resistance, and both move fairly easily. The right gofer drops down cleanly by moving the release coil mech manually.

The right gofer does go up properly in test.

Any suggestions would be appreciated.

Thanks.

Robert

Well, I've tried a bunch of combinations and it seems that the armature in the right gofer is an issue.

I've never seen that before, but I ordered another one from BAA and will see if that solves the issue with the right gofer release mech not working.

No on to the issue of the lower right flipper not working.

Robert

Marc,

No, its a rod similar to a flipper armature except with a groove for a circlip and a slot for the release mech wire. No rubber thing at the bottom.

There is something odd about that armature, the left armature works in the assembly, but when I put back the odd one, the solenoid won't pull the assembly.

In the repeat mode in the solenoid test, I loosened screws and pushed on the armature with my finger. When the armature got about 90% thru it's intended travel, the magnetic force grabbed it and started to move it.

I repeated this several times and finally decided that the armature is screwy. So I ordered another from BAA and will post the outcome.

Thanks for the input.

Robert

NGG Gofer Assy (resized).jpg

Lloyd (Geese Launcher Extraordinaire),

I did that and even removed the Gofer from it's armature to remove the friction of the Gofer and the attaching hardware from the system.

The armature (item 4) still would not retract.

Thanks for the idea.

Robert

After some finesse with the gofer parts, both gofers work as they are supposed to. Not really sure what was causing the hang-up/friction. These gofer mechs are kind of touchy.

So now everything is working. The only issue is the right popper (gofer) activates intermittently during the game; even when there is no ball in the mechanism.

The opto's work in test, and I have looked at the opto board and didn't see anything in particular wrong ( pin burns, cold solder joints, etc.).

Other than just replacing the opto's, what would be a possible diagnostic step. Any idea as to why the popper would have intermittent activation and test OK?

Robert

Thanks, I'll give it a go.

Robert

After cleaning/replacing/re-soldering/testing optos, until I was blue-in-the-face, I finally gave up and replaced the opto board.

Now, the right popper (gofer) has stopped activating intermittently during the game when there is no ball in the mechanism...so all is good.

I can't believe how many hours I spent trying to run this to ground.

Maybe this will help someone else out in the future.

Robert