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STAR* TECH Journal
How To Test For A Faulty
Flyback Transformer
To LooK FoR
SUBJECT
WHAT
How to effectively diagnose a
failed monitor flyback trans-
former.
It should give a sharp rise fol-
lowed by a sharp fall followed by a
smooth fall. If the area where it
should be a smooth fall has ring-
ing ( up, down, up, down, up, down,
etc.) after it, then the flyback is
probably shot.
One "almost" sure-fire way to di-
agnose a bad flyback is to check to
see ifit has any ringing.
VISUAL INSPECTION METHOD
• To do this, power the
monitor up through
an isolation trans-
former powered by a
variac.
• Ground your scope
probe's ground lead to
the monitor chassis.
• Take your scope
probe and place it
near the deflection
yoke.
• Set the scope to 50
uS sweep and about 2
volts per division.
• Slowly power the
monitor up to about
70 or 80 volts and ob-
serve the waveform.
Converting
Main Event
Check Edge
Connector
Kerry Messana
Betson Distributing
Syracuse, New York
PROCEDURE
November 1991
Another way is simply by observa-
tion. Discharge the second anode
to ground (power off, please!) and
clean the fly back off so you can get
a good look at it. Many times,
when they fail, they will blow a
slight hole, crack or swell up.
Bill Johnston
Johnston' Video
Buffalo, New York
PROBLEM
Thanks to Leon Cauchois and his
crack technician Bob "the Ira-
nian" Hussein, we found the solu-
tion to the incompatability of the
audio from our conversion to Trog.
CAUSE
It is due to Konami's JAMMA
edge connector on Main Event not
being fully wired.
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SOLUTION
Add -5 volts, which is missing.
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