Provide more info please... ,what is the motherboard part number.Have you checked to see if there`s a schematic or boardview available,it would be easy to ID it then
You are probably right, but i am asking about this 3 leg component which i cannot recognize. this one was corroded and the laptop have no lcd back light.
See attached. Note the numbers assigned to each pin on this SOT-23 package.
Remove all power. Meter in diode mode.
Place one meter probe to ground (shield is ok) - other meter probe to pin #2.
Do you hear a tone beep? If not, check with pin #3. One of these should tone beep. That pin is ground on the logic board.
Remove this defective component with flux & hot air.
Then apply a piece of wire from pin #1 (aka after the SMD fuse marked '150' shown in the posted picture) AND the other side of the wire to the pin that is NOT ground.
This component, to me, is a slew rate (ie. soft start) load switch to limit in-rush current on the line.
Before starting, confirm that the voltage to ground at the '150' smd fuse is supplying a valid voltage for the display. Respectively, the fault is that there is no voltage after this SOT-23 component?
Confirm the resistance to ground on each pin of this SOT-23 component to be sure there is no shorted rail that caused this component to fail. Excessive current draw can kill a load switch.
Test with and without the display connected to confirm there is no shorted rail linked to this component.
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