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No character or figures
appear.
Turn the brightness control and the
contrast control all the way to the right.
Turn up the screen contro!
and check whether the
raster appears,
Does the entire screen light up ?
Check the signal cable
or computer.
Are the input waveform at
CO-2C pins normal ?
Approx.
0.7Vp-p
Approx.
Are the waveforms at the pins 11, 13, 15
2Vp-p
of 1C3501 normal ?
C3501, its buffer or its drive
circuit (Bright control, Contrast
control, Clamp Pulse, and Blanking
Pulse) is defective.
Are the waveforms of the terminal
Approx.
KR, KG, or KB of CRT socket
45Vp-p
normal ?
Video output circuit is defective.
Q3501
~ Q3506
Q3511
~ Q3513
Heater 6.3V D.C.
G1: —30V
G2 : 300 ~900V
Are the
voltage of terminal Heater,
G1 and G2 of CRT socket normal ?
CRT drive circuit is defective,
FBT, D552, D525
The CRT is defective.
PE 5c ees
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