Service Procedures - Zenith SM-ZVM-122 Service Manual

Page 6-1
SERVICE PROCEDURES
SYMPTOMS AND CHECKS
The following list of symptoms and checks provides
you with some problems you may encounter, and
the most probable areas to check.
SYMPTOM
Monitor completely dead.
(no power to LED)
Hum bars in display.
No
raster.
No high voltage.
No horizontal sync.
No vertical sync.
This list is not intended to be inclusive of all the
problems you may encounter, but rather to provide
you with a systematic approach to diagnosing the
problem. If you encounter a problem not listed in
this chart, analyze where the problem is located by
the way the circuits relate to each other.
AREA TO CHECK
•
Line cord and power source.
•
Fuse FX201 or FX701.
•
Transformer TX201.
•
SWitch SX201 or wiring at switch.
•
Shorted diode, CR701-CR704.
•
Q701-o703, or associated circuitry.
•
LED open.
•
CX707.
•
R707 and R706 interchanged.
•
CR701-CR704, one open.
•
CR706.
•
Black Level or Contrast control turned down.
•
CRT or CRT socket.
•
0201,Q807.
•
RX711 open.
•
Q501 or 0502.
•
Horizontal yoke winding.
•
TX502.
•
CR507, CR508, CR502, CR503.
•
IC501.
•
R502,R503.
•
Horizontal Hold control.
•
C601, R602, R603.
•
Adjust Vertical Hold control.