Service manual

38
TROUBLE SHOOTING
Check PB801 135V
When power isn’t supplied
Output E/W signal in I401 #7
Voltage waveform of Q402 collector is
shown below.
If resistance between Q425 collector and GND
is near 0ߟ, horizontal output TR has been
destroyed. Replace the TR.
High voltage drive
Check F401 #10 (HVG B+135V)
Check R445
Check F401 (High
Voltage Generator)
font
Check F401 #7 (OVP) high voltage
control oscillating waveform
Check R447
Check F401 #8 (HVG B+135V)
Horizontal drive B+ is input to Q403 base
0.5VP-p
0.5VP-p
1000 50Vp-p
5V
NO
NO
NO
END
END
NO
45VP-p
90V
60Hz
60Hz
Check R443
NO