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hi, got a 280-3476-A with no liquid damage and reportedly never dropped. i got chime but no image (not backlight problem) not even on hdmi. after a while of being turned on the fan spins like crazy, i never had this behaviour before so what should i look for?
Pins 28-30 should get 5v at least first few seconds (even without LCD), when power on the board.
At same time pin9 should go to 2.5V; 5V will drop if not.
Post voltage at both pins of L8300, with LCD connected...
"pin 28/29/30 5v without lcd connected"
Check that again.
Impossible to get 5V output if enable pin is low; unless U8300 is bad.
Better to change U8300...