Play Meter

BY Randy Fromm
Motorola's new monitor
Motorola is manuf<:1cturing a new
monitor that's showing up in the
latest video games. The M5000
series (19-inch) and M7000 series
(23-inch) monitors have been in
production since May of this year .
There are some important differ-
ences between the old design and
this latest product . For a clearer
understanding of the new system ,
let's take a look at Motorola's new
baby and the changes they've made .
CONTROLS AND ADJUSTMENTS
With the exception of the power
transformer, the new monitor has all
of the circuitry mounted on a single
printed circuit board . Since there is
no longer a plug-in P .C .B., with 36
interconnection points , all of the
adjustments have been moved from
the chasis to the printed circuit
board itself.
Figure 1 shows the new placement
for the controls . Because the vertical
sync and oscillator sections have
been redesigned in the new system ,
the vertical hold control has been
eliminated from the monitor . The
horizontal hold potentiometer has
also been eliminated , and horizontal
frequency adjustment is performed
by tuning the slug of L1 (horizontal
oscillator) with a hex alignment tool.
The + 73 volt test point is well
marked and located on the left side
of the monitor P .C .B. Unfortunately
the 73 volt adjust has been moved to
the area near the flyback trans-
former . Unless you want your eyes to
light up like a Christmas tree , I
strongly urge that you use a long
plastic screwdriver to make this
adjustment. The + 73 volt adjust can
also be reached from the bottom of
the P .C .B. using a hex alignment
tool.
One important difference between
the new monitor and the XM series is
in the way the C.R.T. (picture tube)
heater is energized . In previous
monitor designs the heater is power-
ed by a 6 .3 volt filament winding on
the power transformer. This makes it
easy to tell if you're getting power to
the mon itor by glancing at the neck
of the C . R. T. If the heater is glowing ,
you know you've got A.C . power to
the unit .
The new monitor takes its heater
drive from a winding on the flyback
transformer . If the power supply or
horizontal sections of the monitor are
bad, the heater in the picture tube
will not light. This is an important fact
to remember when you get to a game
that has a "no picture" complaint.
For a copy of the service manual
for the new monitors, write or
telephone Motorola Data Products,
455 E. North Avenue, Carol Stream ,
Illinois , 60187 . Telephone 312/ 690-
1400. Ask for part number
68p25253a4 7 .
Monitor Circuit Board Detail - Component Location