Black Screen, Led Green, And Osm Present - NEC MultiSync LCD2080UX -BKA Service Manual

2.3 Black Screen, LED Green, and OSM Present

Is there a video signal input available at the input
of ICA01 pins 5, 13 and 20?
NO
YES
Is there a digital signal output available at the output
circuit (In such cases as ICA01 pin 120)?
NO
YES
Is there a digital signal output available at the output
circuit (In such cases as IC4A1 TP4HF)?
NO
YES
Check peripheral output circuits of IC4A1.
Check peripheral circuits of ICA70A.
Is there a clamp pulse signal at ICA01 pin 30?
Check the conditions of
the power supply
IC4A1, clock signals,
inputs, and reset.
Aren't the conditions of the power
NO
supply, clock, and reset normal in
IC4A1 problem?
for
YES
Check conditions of the power supply for ICA01.
Is a horizontal synchronous pulse being inputted to
ICA01 pins 43 and 45?
Is a pulse being input to ICA01 pins 31 and 32?
6-5