Star Tech Journal

S*T J
MARCH 1981
9
Midway ~~Pac-Man" Degree of Difficulty Mod
Figure 1
; -"-
-- i
'-=-'
_ ,
~ -=_ ;
C10
~
+
DIP-SWITCH
2200 f'- F 25V
When this jumper
pad is connected,
the game becomes
more difficult.
0
Atari "Battlezone"
Aux PCB Mod
Stem "Berzerk"
Service Notes
* Symptom: Loss of joystick control
You may experience the following problem
with the "Battlezone" video game.
Symptom:
Screen Freezes
= No motion and no
change in audio.
Cause:
Texas Instruments 74LS374 in Location
C-1 is heat sensitive.
Remedy:
REPLACE Texas Instruments part with
equivalent such as Signetics 74LS374.
*
*
Solution: One direction only:
Failed opto-reflector (mfg.
by Optron: #OPB707)
All directions:
Failed LM339 (Quad Op
Amp)
Screen Ram replacement: use 4027-6
Dynamic Ram
Early models of "Berzerk" may have
had the battery installed backwards.
Symptom: Turning machine from off
to on will award credits. Scrambled
bookkeeping upon power-up.
J