TECH: Flash - Dead Coils

Archived from groups: rec.games.pinball (More info?)

Power off, remove fuses and check with an ohm meter to see if they are good.
If all good, then see if you have power leaving the power supply. LTG

"seast9" <seast9@gmail.com> wrote in message
news:1118865241.820403.58970@z14g2000cwz.googlegroups.com...
> I recently purchased a project flash. When I start the game, the
> lights, sound and scroing switches all work. Unfortunately, all coils
> but the main two flippers don't work. The 3rd flipper, slingshots,
> pop-bumpers and outhole don't work. Where would be the best place to
> start diagnosing?
>

Archived from groups: rec.games.pinball (More info?)

You've got a lot to learn. Chances are right now you have a bad fuse
but there is probably a reason for that.

Go here and bone up.

http://marvin3m.com/sys37/index.htm

Archived from groups: rec.games.pinball (More info?)

"seast9" wrote:
> Thanks for the help. Going through the Marvins guide, I found the
> solenoid fuse on the power supply was blown. I didn't have a 2.5
> slo-blo, so I installed a 2. It blew out within seconds.
>
> How do I troubleshoot this now if I keep blowing fuses?

Get yourself some spare fuses- 5 or 10 of them- 2-1/2 amp or 3 amp slow-blow
are fine. Either that, or get a clip-on circuit breaker that you can
connect via some test leads (saves fuses). Most well-stocked electronics
stores will have these available.

Install new fuse, power up, and check to see if you can hear any of the
coils coming on and locking on right when you turn the power on (before the
fuse blows). Such as a pop bumper energizing, slingshot bumper energizing,
etc.

If so, then focus on that coil as the culprit. Usually in these games the
driver transistor that switches the coil to ground (activates the coil) will
short out, and cause the coil to stay energized. This blows the fuse. If
the fuse is replaced with one that is too high, this can prevent it from
blowing and cause the coil to overheat and short itself out, so check for a
damaged coil (burned up) as well as a possibly shorted-out driver transistor
for that coil.

You should also check the 3 pop bumpers and 2 slingshot bumpers to see if
their "activation" switches are stuck (ie: switches that the ball triggers
to make the bumper work). If one of these is stuck closed, it will keep the
coil turned on, and cause fuse to blow.

If you can't find any coils in the game that are coming on and staying on
when you power-up, then what you will have to do is isolate the offending
coil by process of elimination. Probably the easiest way to quickly narrow
it down is by removing a couple of connectors from the left side of the
driver board in backbox.

If you remove the 2nd connector down, this will cut out the slingshots and
pop bumpers. If you can power on the game without fuse blowing in this
state, then one of your pop bumpers or slingshot bumpers is to blame. You
can then remove the low wire from each coil (non-red wire) and re-connect
each until you find the one that causes the fuse to blow. At that point you
either have a shorted coil, shorted coil diode, or possibly a shorted driver
transistor (TIP102) for that coil on the driver board in backbox. Could
also be something else (another electronic component) further upstream, but
usually it's just the TIP102 transistor.

If not (fuse still blows) then re-connect the 2nd connector down and remove
the 3rd one down. Try powering up again. If fuse doesn't blow, then one of
your other playfield coils is to blame (ball kickout, one of the drop target
bank reset coils, or right saucer kick-out. Remove coil low wires, and
isolate one at a time as described above.

If fuse still blows with 3rd connector down removed, then re-connect it and
remove the 5th one down (very bottom left corner- brown wires). Power up,
and if fuse doesn't blow, then it's most likely a shorted/siezed knocker
(replay) coil located in the main cabinet.

There's several other things that can cause this problem and a lot more
possibilities and things to check, but way too much for me to type here- I
could sit here all night.... But the above is the "usual case" scenario and
should at least hopefully help you get started in narrowing down where it's
coming from.

We have replacement fuses, fuse kits for various games, and replacement
driver transistors as well as coils, etc. See our site at:
www.actionpinball.com if you need to order any new parts.

Hope that helps!

Ray J.
--
Action Pinball & Amusement, LLC
Salt Lake City, Utah USA
Web: www.actionpinball.com

We're serious about pinball. Anything else is just for fun!