Table Of Contents - Zenith ZVM-131 Service Manual

Characteristics ................................ 5
Description .................................... 5
Controls, Indicators, and Connectors. . . . . . . . . . . . . .. 5
ZVM-131 and ZVM-135 ....................... 5
ZVM-133 and ZVM-136 ....................... 6
ZVM-131 Specifications.......................... 7
ZVM-133 Specifications . . . . . . . . . . . . . . . . . . . . . . . . .. 8
ZVM-135 Specifications . . . . . . . . . . . . . . . . . . . . . . . . .. 9
ZVM-136 Specifications . . . . . . . . . . . . . . . . . . . . . . . . .. 9
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
ZVM-131 and ZVM-135 Installation ............... 10
Composite Signal ........................... 10
RGB Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
ZVM-133 and ZVM-136 Installation .. . . . . . . . . . . . .. 13
Circuit Descriptions .......................... 14
ZVM-131 and ZVM-135 Circuit Boards ............ 14
Main Board ................................ 14
Start-Up and Operating Voltages . . . . . . . . . . .. 14
Degaussing Circuit . . . . . . . . . . . . . . . . . . . . . . .. 14
Power Supplies .......................... 14
+
150 VDC Supply ....................... 14
+
26 VDC Supply ........................ 15
+
12 VDC Supply ........................ 15
RGB Drive and Cutoff Voltages . . . . . . . . . . . .. 15
Composite Drive.... . . . . . . . . . . . . . . . . . . . . .. 15
Composite Vertical Sync . . . . . . . . . . . . . . . . . .. 15
Composite Horizontal Sync . . . . . . . . . . . . . . . .. 16
Horizontal and Vertical Drive Outputs .. . . . . .. 16
AudiolVideo Sync Board ..................... 16
High Voltage and Horizontal Sweep Board . . . . .. 16
Width Step Board . . . . . . . . . . . . . . . . . . . . . . . . . .. 16
Video Output Board ......................... 16
ZVM-133 and ZVM-136 Circuit Boards. . . . . . . . . . .. 17
RGB Gain Control Board . . . . . . . . . . . . . . . . . . . .. 17
RGB Input Signal. . . . . . . . . . . . . . . . . . . . . . . .. 17
RGBI Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18
Safety and Service Guidelines . . . . . . . . . . . . . . . . . .. 18
AC Leakage Test ............................. 18
Other Precautions ............................. 19
Suggested Tools and Supplies .................. 19
Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
Troubleshooting ............................... 19
Fault Isolation Procedures ...................... 20
CONTENTS
Alignments and Adjustments .................... 21
Main Board Adjustments ..................... 21
RGB Cutoff and G2 Adjustments. . . . . . . . . . .. 21
RGB Drive Adjustments ................... 21
Vertical Center and Vertical Height Adjustments. 21
Horizontal Center and Width Adjustments . . . .. 21
Horizontal Oscillator Adjustment . . . . . . . . . . . .. 24
+
95 Volt Adjustment. . . . . . . . . . . . . . . . . . . . .. 24
Sweep Assembly Adjustments . . . . . . . . . . . . . . . .. 24
Focus Adjustment ........................ 24
Width Selection .......................... 24
AudioNideo Sync Board Adjustments .......... 24
Chroma Null Phase Adjustment . . . . . . . . . . . .. 24
BLUE and RED Cutoff Adjustments ......... 24
Cleaning Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
Performance Tests ............................ 26
Fill the Screen Test . . . . . . . . . . . . . . . . . . . . . . . .. 26
Color Bar Test ............................. 26
BASIC Program ............................ 27
Servicing Diagrams ............................ 27
Disassembly/Reassembly ....... . . . . . . . . . . . . . .. 49
Back Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
Top Cover .............................. 49
Video Output Board . . . . . . . . . . . . . . . . . . . . . .. 49
Input Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
High Voltage and Horizontal Sweep Assembly. 49
CRT .................................... 49
Primary Control Board . . . . . . . . . . . . . . . . . . . .. 49
AudiolVideo Sync Board . . . . . . . . . . . . . . . . . .. 50
Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 50
Speaker .........................
# • • • • • • •
50
Secondary Control Assembly (ZVM-131 and ZVM-
135) .................................... 50
RGB Gain Control Board (ZVM-133 and ZVM-136)
........................................ 50
Parts List ................................... 51
Figures
1. Monitor Front View ......................... 5
2. ZVM-131 and ZVM-135 Controls and Connectors. 11
3. ZVM-133 and ZVM-136 Controls and Connectors. 12
4. AC Leakage Voltmeter Circuit ............... 18
5. Main Board
Adjustment~
.................... 22
6. High Voltage and Sweep BoardlWidth Step Board Ad-
justments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23
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