Star Tech Journal

STAR*TEcH
Journal
Mike
April 1995
Houpy
•
Coin-Op
BBS
•
Dallas,
Texas
BROMLEY
SMS/CoASTAL
RocK8-BowL
AMUSEMENT
LOCKED-UP GAME
PoPABALL
NoC01N UP
SYMPI'OM
The game seems to be locked up,
or dead. The lights are not flash-
ing, the scraper motor doesn't run,
there is no sound when a coin is
put into play, and/or there is no
coupon payout when a target is
hit.
Possrnn.rrrns
1) Check the Display Board that
is located on top of the cash box.
Try to enter Audit Mode.
If you cannot, or do not see the
LED display lit, tum the game off
and then back on to see if the
scraper motor runs. If it does not,
proceed to the next step.
net and has two fuses mounted on
it. There is a good chance that the
pin in the plug which supplies the
power from the transformer to the
Power Supply board has become
corroded, burned, or oxidized
and is no longer making good
electrical contact with the pin on
the power supply board.
If this is the case, you may have
to replace the pins in the plug
and/ or the pins on the power sup-
ply board itself.
CAUTION
This repair should be performed
with the power off to the game.
The game does not coin up. In-
stead of the normal +5 volts on
the coin switches, there is a much
lower, but still readable, voltage
present.
POSSIBILITY
Check that the voltage in the plugs
which go to the coin switches is
not +5 volts even when the plugs
are not connected to the coin
switches.
If the voltage remains around 1.63
to 1.93 volts, check U60, which is
an 8255 Microprocessor.
This microprocessor is unbuffered
so that the inputs from the coin
switches go directly into this chip.
2) Check the 5-pin Molex con-
nector which is on the Power Sup-
ply board for burned pins.
This plug is J 1. Check the Orange
wire, which is Pin =II= 1, in particu-
lar. The Power supply board is the
lower of the two boards which are
mounted on the inside of the cabi-
PROBLEM
~i l!Y,ti, =e-,:j
Journal
It could be that you had a wire
shorted that goes to the coin
switch which knocked out the
8255/U60 IC.