Archived from groups: rec.games.pinball (
More info?)
"M D" wrote:
> The flippers on our High Speed are somewhat weak.
> They have been completely re-built with all new parts and then parts
> were changed around to make sure all parts were good. And when I say ALL
> parts, I mean everything but the base was replaced!
> I would like to test the voltage to make sure it is good.
> I am thinking the little board on the right hand side in the lower
> corner is the supply for the flippers and that the bridge might be weak.
> Is this correct? Is there a test point on that board?
No test point, but you can measure at the output connect on the appropriate
pin(s).
Better to measure at the coil- that's where voltage counts. Measure from
any coil lug to ground to get a reading. With filtered 50vdc you should see
something around 70vdc at the coil.
However, "voltage" is not what makes your coil strong or weak. It's current.
If all the mechanical parts are in good shape and installed/adjusted
properly and the coil and EOS switch are wired properly, then all you need
is good current to get the flipper to work right.
These coils draw/require a lot of current, and to get enough current through
the coil, you have to have good connections all through the circuit. From
the flipper power board to the coil, through the EOS switch, from the coil
through the playfield and main cabinet wiring harnesses and connectors, to
the flipper button switch, through the switch, then back to the MPU board,
onto the board, and through the enable relay to ground. Any bad spot in
there can limit current and make for a weak flipper.
One hint as to whether your problem is on the hot (power) or cold (ground)
side of the coil is whether BOTH flippers have the same problem, or just
ONE. There is basically one power line to both coils (or maybe just to the
flipper power board in this game, then 2 separate power lines out to each
coil- check your schematics to be sure), then two separate ground (low)
lines going away from the coils. So if you have a problem with just one
coil, that's usually a problem on the low side of the coil (not likely both
low lines would be bad).
If BOTH flippers have the same problem, then start looking on the hot
(power) side.
One place you may want to start with is the bridge rectifier on the flipper
power board. These can go bad over time (very common failure parts in these
older games- the one on the flipper board and the one on the main power
supply board above) and when they do go bad, they will either short out
completely (blow fuses, no flippers work), open up (no flippers work), or
partially short/open (decrease in voltage and/or current = weak flippers).
So maybe start there. Taking a voltage reading may tell you if the bridge
is bad if the voltage is considerably lower than expected.
Another test you can do is to ground the low side of each flipper button
switch, and activate the flippers by the usual method (flipper buttons) and
see if any change in performance. Grounding the low (non-coil) side of each
switch in the main cabinet bypasses the rest of the circuitry back to the
MPU board and through the enable relay, so if there is a problem there, this
will bypass it, and your flippers will become strong again, all of a sudden.
And don't overlook bad/worn-out flipper button contact points. We replace a
LOT of flipper button switches in these old games because they simply wear
out over time and get pitted/worn and won't let enough current through to
keep the flippers working good.
We have all of these replacement parts available if you need any for your
game- the rectifiers and filter cap on main PS board are a must for
replacement- highly recommended. See our website at: www.actionpinball.com
for more info, pictures, prices, online ordering.
Hopefully the above will get you on the right track.
Good luck!
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!
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