3. The raster don’t appear.
The raster don't appear
Is the C425= -200V
normal?
Does the CRT heater
glow red?
Does the entire screen
light up?
Turn the FBT screen
clockwise
FBT is defective
R457, D420 are defective
Is the voltage at the heater
pin9 of CRT socket
normal?
D206,Q208 are
defective
Heater voltage
approx. 6.3V
Video circuit Q419, Q420
IC301 pin29 brightness
control are defective
No
Yes
Yes
No
Yes
No
No
40
ViewSonic Corporation
Co
nfidential - Do Not Copy
70f+SB-3
E
Summary of Contents for E70F - 17" CRT Display
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