Motorola M3000 Service Manual

GENERAL INFORMATION
The monitors described herein are fully transistorized (ex-
cept CRT) and applicable for displaying alphanumeric
characters. The/M3000/M3003 series monitors use a 12-
inch CRT and the M4000/M4003 series monitors use a
15-inch CRT. All monitors utilize a non-composite video
signal with separate TTL horizontal and vertical sync pulses.
(See Schematic diagram.)
The CRT's employed are of the magnetic deflection type
with integral implosion protection. An operating voltage of
+70 volts DC is required from the regulated power supply
for both models. A universal power transformer permits
operating the monitor from either 115 or 230 volts AC,
50/60 Hz.
Input and output connections for the monitor are made
through a 10-pin edge or header connector on the vertical/
video circuit card. Inputs consist of video, horizontal/
vertical sync, and signal ground. One additional input,
TTL level StepScan, is also connected to the monitor
via the 10-pin edge connector. Output connections are
provided for an optional remote brightness control.
Circuitry consists of two stages for video amplification, five
stages for vertical sync and deflection processing, five stages
for horizontal sync and deflection processing, and a regu-
lated +70 volt power supply. Both models also have dynam-
ic focusing and StepScan amplifier. (See Schematic dia-
gram.)
Three etched circuit cards are utilized, containing the
vertical/video circuit, horizontal circuit, and power supply
circuit. An optional low voltage logic power supply is avail-
able when a remote power source is required for logic
interface circuitry. Components are mounted on the top of
the circuit cards and plating copper foil on the bottom.
Schematic reference numbers are printed on the top and
bottom of each circuit card to aid in the location and iden-
tification of components for servicing. All standard oper-
ating/adjustment controls are mounted in a convenient
manner on the three circuit cards. Refer to Motorola
Service Manual VP20, Part No. 68P25253A40 for com-
plete service info~mation on the low voltage logic power
supplies.
SERVICE NOTES
CIRCUIT TRACING
Component reference numbers are printed on the top and
bottom of the three circuit cards to facilitate circuit
tracing. In addition, control names and circuit card termin-
al numbers are also shown and referenced on the schematic
diagram in this manual.
Transistor elements are identified as follows:
E - emitter, B - base, and C - collector.
COMPONENT REMOVAL
Removing components from an etched circuit card is facili-
tated by the fact that the circuitry (copper foil) appears on
one side of the circuit card only and the component leads
are inserted straight through the holes and are not bent or
crimped.
It is recommended that a solder extracting gun be used to
aid in component removal. An iron with a temperature
controlled heating element would be desirable since it
would reduce the possibility of damaging the circuit card
foil due to over-heating.
The nozzle of the solder extracting gun is inserted.directly
over the component lead and when sufficiently heated, the
solder is drawn away leaving the lead free from the copper
foil. This method is particularly suitable in removing multi-
terminal components.
When replacing "plug-in" transistors, please observe the fol-
lowing precautions:
1. The transistor sockets are not "captive", which means
that the transistor mounting screws also secure the socket.
When installing the transistor, the socket must be held in its
proper position.
2.' When replacing a plug-in transistor, silicone grease
(Motorola Part No. 11 M490487) should be applied evenly
~..:i the top of the heat sink and bottom of the transistor.
In addition, be sure a mica insulator is positioned properly
between the transistor and heat sink.
3. The transistor mounting screws must be tight before
applying power to the monitor. This insures proper cooling
and electrical connections. NON-COMPLIANCE WITH
THESE INSTRUCTIONS CAN RESULT IN FAILURE OF
THE TRANSISTOR AND/OR ITS RELATED COMPO-
NENTS.
NOTE
Use caution when tightening transistor mount-
ing screws. If the screw threads are stripped by
excessive pressure, a poor electrical and me-
chanical connection will result.
CRT REPLACEMENT
Use extreme care in handling the CRT as rough handling
md\' cause it to implode due to high vacuum pressure. Do
not nick or scratch glass or subject it to any undue pressure
in removal or installation. Use goggles and heavy gloves for
protection. In addition, be sure to disconnect the monitor
from all external voltage sources.
1. Discharge CRT by shorting 2nd anode to ground;
then remove the CRT socket, deflection yoke and 2nd
anode lead.
4-18

Motorola M3000 Specifications

General

Brand	Motorola
Model	M3000
Category	Cordless Telephone
Language	English