Star Tech Journal

(
Prem.ier
Silver Slugger
1'9',
Troubleshooting The Switch Matrix
Evan Wessel
Mercury Amusement
Havertown, Pennsylvania
PROBLEM
Every time the right or left flipper
is activated, all the switches in
their respective return line are
activated.
r - LAMP - •
MATRIX
The lane change is activated by a
sensor board that signals the
CPU when the flipper is ener-
gized. When this board is discon-
nected, the problem goes away.
Everything on this sensor board
seems to check out ok.
RETURNS
L _ _ (8)
___
J
+ 20V DC
. - - - - - +5V DC
. .
: . . .............
P4 .
~
.
P3
" ............ .
14
10
The symptom is that of a matrix
driver shorted to ground, either
in the wiring or on the logic
board, or one of the returns be-
ing shorted to ground. It could be
almost anywhere. the playfield,
the logic board, or that board
that checked OK. Try looking at
the strobe and return with a logic
probe.
•
6
A3
DRIVER
BOARD
18
i""""" "" " ••••• 11
The matrix problem in the Silver
Sluggerwas caused by a shorted
lamp driver transistor of all
things. Apparently. this problem
was caused by someone shorting
across the coin switch terminals.
frying a diode and taking out the
driver board.
:
r-------
PROBLEM
CAUSE
1
i
P5
:
8
i''''p7' •••
LAMP ANO
SOLENOID
GROUNDS
I, .......
18
, .... .........
.
f P6 l