Zenith Data Systems SM-ZVM-134 User manual

Copyright © 1983
Zenith Data Systems
All Rights Reserved
SM-ZVM-134
Color Monitor
ServiceManual
SAINT JOSEPH, MICHIGAN 49085
585-23
First Printing
Printed
in the United States of America

II
•
•
•
•
•
CAUTIONS ... WARNINGS
When you are servicing the ZVM-134 Moni-
tor,
under no circumstances should you alter
or modify its design without permission from
ZenithData System.
Replace all components with the original
parts listed
in Replacement Parts List in this
Manual.
The
CRT uses integral implosion protection.
The yoke is permanently bonded to
the CRT.
Do not attempt to separate the yoke from the
neckof the
CRT.
NOTE: Reference to Hot Ground and Cold
Ground are madethroughout thetext.
Hot Ground is an AC hot ground. It is taken
from the metal plate located
on the right side
of the monitor that holds the sweep assembly
together.
Cold Ground is a DC cold ground. It is taken
from the
main chassis across the top of the
monitor.
•
•
Discharge the high voltage lead going to the
anode of the
CRT. One method of discharging
it is to use a screwdriver
and a 12" jumper
wire with an alligator clip on each end. Clip
one alligator clip to the chassis
or to the DAG
connector on the CRT, and place the otherone
on your screwdriver. Then slide the end of
the screwdriver
under the high voltage cap
at the anode of the
CRT. Refer to the illustra-
tion below.
We recommend that you use an isolation
transformer
when you are working on this
Monitor.
Illustration 1
High Voltage lead discharge

III
Table of Contents
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . .. 1-1
SPECIFICATIONS
.... . . . . . . . . . . . . . . . . . . .. 2-1
INSTALLATION AND START UP
.......... 3-1
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-1
Cable Description ........................ 3-1
Cable Connection . . . . . . . . . . . . . . . . . . . . . .
.. 3-3
GreenIWhite Switch . . . . . . . . . . . . . . . . . . . .
.. 3-3
On-Off Switch . . . . . . . . . . . . . . . . . . . . . . . . .
.. 3-4
THEORY OF OPERATION
................ 4-1
Input Voltage ........................... 4-1
Degaussing Coil
......................... 4-1
Horizontal
Output Transistor .............. 4-1
Modules
................................ 4-2
Main Board
........................... 4-2
Sweep Assembly . . . . . . . . . . . . . . . . . . . . .
.. 4-2
Video
Output Board . . . . . . . . . . . . . . . . . . .. 4-2
RGB Input Signal . . . . . . . . . . . . . . . . . . . . . . .. 4-2
DISASSEMBLY
.......................... 5-1
Back Cover ............................. 5-1
Video Output Board . . . . . . . . . . . . . . . . . . . . .. 5-2
Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 5-3
Sweep Module
and High Voltage Section ... 5-4
CRT
................................... 5-6
On-Off
Switch. . . . . . . . . . . . . . . . . . . . . . . . . .. 5-8
SERVICE PROCEDURES .................. 6-1
Quick Checks
........................... 6-1
Conditions Symptoms
and Checks ......... 6-2
Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-3
Measurements
.......................... 6-16
REPLACEMENT PARTS LIST
.............. 7-1
Exploded View . . . . . . . . . . . . . . . . . . . . . . . . .. 7-1
Horizontal Width Sweep Assembly ......... 7-3
Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 7-4
CIRCUIT BOARD X-RAYS VIEWS
........................ fold-out from 8-1
SCHEMATIC DIAGRAMS
.............. fold-in

IV

Introduction
The ZVM-134 is a high resolution Color Monitor
which accepts direct RGB video inputs, displays
twenty-five 80-character lines, has
20 MHz
bandwidth and 20 ns rise time, and uses modular
chassis designfor ease of service.
This Monitor is certified to comply
with the limits
for a class B computing device
pursuant to subpart
Jofpart 15 of the FCC rules.
Service of
the ZVM-134 is to board level. When you
determine that a circuit board is at fault, it
must
be replaced. Return the defective board to your Ze-
nith Data Systems Distributor.
Page 1-1
Tools and test equipment required for servicing the
ZVM-134 monitor:
•
1/4" nut driver
•
1/4" long shank nut driver
• 1/4"flat screwdriver
• Needle-nose pliers
• Digital voltmeter
• Oscilloscope
• Isolation transformer
• Software-ZDOS
with VMEMTEST
• ZBASIC

Page 1-2

Specifications
Operating Voltage .......................... .
Operating Current
.......................... .
Normal Power
............................. .
Nominal High Voltage
...................... .
Fuse Protection
............................ .
Input
..................................... .
CRT ..................................... .
Pixel Display
.............................. .
ColorlMonochrome Display
.................. .
Size
...................................... .
Page
2-1
120 V AC 60 Hz.
"E" version: 240 VAC, 50 Hz.
.87 Amps maximum.
69 Watts.
33kV.
4 Amp, type FX3201.
DB-15 type connector.
RGB signals-TTL positive (Analog, 0-5 V).
Composite sync -TTL positive or negative (Analog,
1-5 V).
Horiz sync -TTL positive or negative (Analog,
1-5 V).
Vert sync - TTL Positive or negative (Analog,
1-5 V).
Ground.
13",90 degree, .43
mm fine pitch dot mask.
26 kV
at 0 beam.
450jJ.A max beam current.
100 voltcutoff.
Internalmagnetic
shield .
.7
mm maxconvergence error.
Sealed systemtube, yoke, beam-bender.
640 x 250.
GreenlWhite switch.
13.5"H x 20"W x 15"D
Zenith Data Systems reserves the right to discon-
tinue products
and to change specifications at any
time
without incurring any obligation to incorporate
new features in products previouslysold.

Page 2-2

Page 3-1
Installation and Start Up
LOCATION
The ZVM-134 Monitor should be located near an
AC power source, and in an arfla which will provide
proper ventilation. There are vents on the bottom,
back, and top of the cabinet
which permit air to flow
through the cabinet, keeping the components cool.
Be sure these vents are notblocked.
CABLE DESCRIPTION
The following two RGB cables are available for the
ZVM-134 Monitor.
CABLE
ZVM-134-1
ZVM-134-Z
ZVM-134-3
COMPUTER
Z-100 family ofcomputers
IBM
Apple
CAPt./!- /I
-z,VII"'/1¥-/
PIN SIGNAL 'I
Plr( T~ J"1JI8IJ
1
-H
8
2
+H
3 not used
4
+V
'I- 2. 4 OJ/.~""
5 G To
6 B 5 z0
().J7- G It J)
7 R 3
:Z () I) J(.,
8 not used
9
-V
9
10 not used
11 GND
2.
12 not used
13
not used
14
not used
15
not used
.j"HEi.C.-(SHI6I.ijJ----- S/f1Z tL
NOTE: Composite sync can be used. However, nega-
tive composite sync
must be applied to both pins
1
and 9, or positive composite sync must be applied
to both pins 2
and 4. This will require a modified
cable.
The connectorpinout for the
RGB cable is as follows. ~ ~
Refer to Figure 3-1. ~ ~ \l ~ ~ ~ ~ ~ \\ \\ \\ \\
Figure3-1
Connector pinout
I !j
,-~.-
FROM COMPUTER
t..o==='" .•

Page 3-1
Installation and Start Up
LOCATION
The ZVM-134 Monitor should be located near an
AC power source, and in an area which will provide
proper ventilation. There are vents
on the bottom,
back,
and top of the cabinet which permit air to flow
through the cabinet, keeping the components cool.
Be sure these vents are not blocked.
CABLE DESCRIPTION
The following two RGB cables are available for the
ZVM-134 Monitor.
CABLE
ZVM-134-1
ZVM-134-2
ZVM-134-3
COMPUTER
Z-100 family ofcomputers
IBM
Apple
PIN SIGNAL
1 -H
2 +H
3 not used
4 +V
..... f\'M.o- 5 G
.............. - 6 B
R
not used
9 -V
10 not used
Z6tf IrH CA".e 1:/
7-(11'13,-21
Fo~ V.cp IJ/"f .IBn PC
9iJiff 0 TfJ.,t'Bi/
,
9
~
--11 GND 2-
12 notused
13
not used
14 not used
~ ;'\
15 not used , {£", ft-", "" IIfS1'NU"J
.rtlGt~ (S"/I&,(.IJ SHetl
NOTE: Composite sync can be used. However, nega-
tive composite sync must be applied to both
pins
1 and 9, or positive composite sync must be applied
to both pins 2
and 4. This will require a modified
cable.
The connector pinoutfor the
RGB cable is as follows. \\ \\
Refer to Figure 3-1. ~ ~ ~ \\ \\ \\\\ \\\\ \\ \\ \\
Figure 3·1
Connector pinout
I
'I
,- ....
FROM COM PUTER
'-="'~"-