ViewSonic A90f+-1 VCDTS23307-2R Service Manual page 32

SECTION 2
Blank Screen LED
Amber
Power on again to check if
any message on screen
NO
No
Check pin 23,21of IA01
Pin23= High, pin21= Low
ViewSonic Corporation
YES
Check signals from PC
NO
Check if XA01
waveform exist ?
YES
Replace
MCU (IA01)
29
Check: IA01 sync. input pin41
Connectors P901, P902
NO
Check B+(5V)
to IA01 exist ?
Confidential – Do Not Copy
and pin42
A90f+-1