Folks and Medusa enthusiasts,

I had a strange failure happening to me this past weekend. A friend came over and apparently likes to play holding the flipper button depressed most of the time. This bad habit resulted in one of the upper flipper coil staying locked, burning the plastic sleeve, locking the flipper in the wrong position and burning the general fuse, with a screeching halt and a dark playfield.

First I am puzzled that the 1 Amp Slow-blow fuse on the playfield did not take the brunt of the vicious attack...... Instead the 110VAC fuse took the entire machine down.

Anyway, after looking at what may have happened, I replaced the main fuse, quickly changed the coil, re-adjusted the double contacts on the zipper flippers and was in business shortly after.

medusa-flippers (resized).jpg

If you look at the schematics, you do not get a very clear picture of what is taking place in this machine. My understanding (and I could be wrong) is the following (correct me please):

1) The power is sent to the zipper flippers (upper playfield) first.
2) The zipper flippers when reaching their end of stroke, send power to the lower flippers.
3) The lower flippers have their own EOS device plus an additional switch to cut the lights under the flipper bats.

I find this stuff highly inefficient and was thinking about re-wiring the lower flippers directly (with a slow-blow fuse of course) so that they are powered directly by the flipper buttons. I can thus, bypass the lousy switch assembly on the Zipper flippers and simplify it to a single EOS on the zipper flippers.

Granted, the flipper buttons will now see twice as much current than before. I suspect they can handle the extra load with no problem and they are a lot more accessible for maintenance than the zipper Flipper contacts located on the upper playfield.

What do you guys think and have you done such modification, or something different?

Thanks for chiming in.

Yves

Maybe I should have posted this to the Medusa Club owners forum.....too.

Quench, Zacaj and Dothedoo,

Thank you for your explanations and suggestions. I will check my machine again to see which pair of flippers is wired first.
My Medusa is one of the last ones built #3490 and the wiring may have been modified from the early machines.

I also suspect that a slow-blow fuse may have been installed in lieu of the fast blow F4.

I did not think about the slight delay or staggering of the coils firing. It does make sense to do it the way it was done, as Bally Power Supplies are notoriously undersized.

I will change all the contacts and probably redo the wiring with greater gauge and fresh wires. It should improve the firing dramatically.

Thanks
Yves