International Arcade Museum Library

***** DEVELOPMENT & TESTING SITE (development) *****

Star Tech Journal

Issue: 1990-August - Vol 12 Issue 6 - Page 4

PDF File Only

Merit Pub Time II
Plus 2 New Epro1n
Jim Kelly
W1ns Black Knight
2000 Lock-Up
Merit Industries
Bensalem, Pennsylvania
Service Shop
New England Pinball Service
Derby, Connecticut
PROBLEM
PROBLEM
If a coin is inserted while the game is producing
musical sounds, the game will lock up. The game
would have to be turned off, then on again to
clear. The game would retain your credit and you
could continue play.
We have received 9 BK-2s for service, all with the
same problem - when the start button is pushed
the game locks up.
CAUSE
Loose set screws.
SOLUTION
There is a new updated program Eprom avail-
able through your local Merit distributor. This
Eprom is located on the main logic board
(RDP0l) in the back of the target section.
INSTALLATION
Remove the original Eprom in location U7 (Pro-
gram #4378-01 U7-0, OAorOB). Replace it with
updated Eprom program #4378-01 U7-OC. If
there are any questions call Merit Customer
Service at 1-800-445-9353.
SYMPTOM
The wheel that moves the draw bridge up and
down has a set screw that holds it onto the travel
motor. If the screw loosens up while the bridge is
mid travel, the wheel will not activate the up or
down micro switches. This will shut the game
down.
SOLUTION
When retightening the set screw, be sure that
the screw is on the flat of the motor shaft. Apply
a small amount of Lock-tite to prevent any reoc-
currence.
W1ns Black Knight 2000 Opto Targets
Evan Wessel
Mercury Amusements
Havertown, Pennsylvania
PROBLEM
SOLUTION
I have been having a problem with the drop
targets not resetting properly. Sometimes they
just stay down all the time.
I had that problem where jiggling the drop target
PCB would bring the targets up and it turned out
to be a bad optocoupler. Try checking for dirt on
either side of the opto (photo-coupler) . Cleaning
both sides of the opto will often solve the problem
you describe.
I checked for bad solder joints and also checked
for bad connections on the molex connectors but
have found no sign of a problem. I seem to be able
to fix it temporarily by wiggling the boards a
little.
If not, try replacing all of them and that should
fix the darn thing. Oh, I miss the old fashioned
microswitches. Who said fancy is more reliable?

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