Sony KV-27EXR25, Техническая сервисная информация

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TROUBLESHOOTING
POWER SUPPLY
Check AC Fuse 1.
1 is open:
Check Bridge Rectifier Diodes and Resistor
Capacitors. Electrolytics
and Power Converter IC (IC65 and Power Transformer
Apply 120V and check for at the (+) lead of
If is missing:
Check Line Filters Power Transformer
Capacitors Electrolytic and
If is present, check for at the (+) of
If is missing:
Check the voltages, waveforms, and components associated
with Power Relay
and Relay Driver Transistor
and D601.
Note: The set may be in shutdown. Refer to the “High Voltage
Shutdown” section of this Troubleshooting guide.
If is present at the (+) lead of check for the proper wa-
veform at pin 1 of 1.
If the waveform is missing:
Check the voltages, waveforms, and components associated
with
1, Transfer IC Converter Transformer
and Soft Start Transistor
If the proper waveform is present at 1 of 1:
Check the voltages, waveforms, and components associated
with T6.5 1.
* Taken from isolated ground.
HIGH VOLTAGE SHUTDOWN
high voltage is monitored by D531, rectifying pulses
from the Horizontal Output Transformer Should the high
increase, the rectified voltage at the cathode of Diode D531
will also increase, This will cause the voltage at pin 8 of Protect
Module (PM501) to increase and
on Protect Transistors
which causes Relay Drive Transistor (4601) to turn off and
remove power from the set.
To troubleshoot, remove Resistor R629 fom the circuit. Use a
for AC power. Start at 90VAC and increase as to locate
and repair the defect. Return R629 to the circuit.
Note: Care should be taken in defeating the high voltage shutdown
circuit, as this may cause excessive X-radiation and damage the
CRT,
and associated components. Monitor the high voltage
and troubleshoot.
HORIZONTAL
Determine if the TV in shutdown:
Refer to the “High Voltage Shutdown” section of this
Troubleshooting guide.
If the TV is not in shutdown, inject a horizontal signal at the base of
the Horizontal Output Transistor
If horizontal deflection is now present:
Check the voltages, waveforms, and components associated
with pins
and 45 of Y/C/J IC and
Horizontal Drive Transistor
If there is no horizontal sweep:
Check the voltages, waveforms, and components associated
with
and Horizontal Output Transformer and
check components associated with Diodes 17, 19, D520,
D521, and D531 for defects.
The high voltage rectifier is part of and if defective will effect
the performance of the horizontal circuits.
If the horizontal oscillator is off frequency:
Check the voltages, waveforms, and components associated
with AFC-DET Transistor
and Buffer Transistor
Horizontal linearity or problems may be caused by Capaci-
tors and beiig defective.
VERTICAL
Inject a vertical drive signal at pin 3 1 of Y/C/J IC
If vertical deflection is now present:
Check the voltages, waveforms, and components associated
with pins 29
and 44 of
If there is still no vertical deflection:
Check the voltages, waveforms, and components associated
with Vert Out IC
Vertical linearity or problems may be caused by pincush-
ion, vertical feedback and circuits:
Check the voltages, waveforms, and components associated
with Pin Correction IC (IC531) and Pin Out Transistor (4530).
Also check Electrolytics C328, C563, and
for defects.
IF-AGC
Inject a video signal at the IF input and check for video on the CRT.
If video is present:
Check the tuner, tuner control, and tuner AFC circuits.