hi all pinsiders

Picked up a Who Dunnit recently which had a couple of minor problems
and one that really needs sorting.

The flipper fuses blow - firstly the left hand flipper fuse - it will blow after about
2 minutes of playing, the other flipper fuse doesn't seem to blow if that one
has - but it has blown before the left fuse once (hope that makes sense).

Then after a couple of times of this happening - the flippers twitch (i.e. they
flip of their own accord until the fuse blows) From memory i think that the
twitches are independent of one another - meaning that they don't necessarily
twitch at the same time.

I have tested the cabinet switch optos which are fine - and indeed in game with
no blown fuse - the flippers do work when you hit the button and stay up
when held.

I changed the coils with some old (but working) ones i had from another machine
as i thought this the most likely thing - but it is exactly the same.

Could it be the fliptronic main board? The wiring seems tight and the EOS switch
seem to work ok - plenty of space between wiring and both work in test mode.

Thanks for any help.

Thanks for the help cody

On re-inspection actually there may be a problem with the optos.
In switch edges the switch opening square flashes suggesting it's going on/off quickly?
Both buttons do the same.

When playing and holding down a flipper button - the flippers do stay up so surely
the EOS should be held on?
but there is a pretty loud sound from the coils (with audio off you can clearly hear it).
The coils were certainly warm if not hot after a 5/10 minute game which luckily the
fuses didn't blow - yep they are SB

Thanks in advance.

Thanks jwo.

The optos are almost immaculately clean - i cleaned them anyhow
but..same thing - in switch edges the open/closed flashes when triggered
and...so ruling out now flipper problems - when one is pressed, the other
can flash on/off also.

I took an opto out of another machine (which has always been fine) just
to make sure - and indeed that does exactly the same thing.

So - could this be a wiring/board problem?

Only one thing for it - should've done this ages ago - fliptronics is coming out of dredd....
will let you know, really appreciate the help.

Same thing with the Dredd Fliptronics hmmmm...

Yeah EOS is fine, i guess this has to be the wiring from the optos?
The Who Dunnit fliptronics is fine in Dredd also.

Probably the coil is going mad having the switch go on/off so rapidly?