Re: Lenovo 100-15idb NM-A681 no turning on
Yes. Agree that this component is likely defective.
You can check the same resistance values on the component while it is on your work table.
Check the resistance between:
source & drain
source & gate
gate & drain
There are 2 such mosfets inside this single package so check both.
A low resistance on any of the above checks means the mosfet is defective.
With the logic '1' = ~3v on the gate on a 2N7002, the mosfet should be ON.
When the mosfet is ON, the lower resistor on the above portion of the schematic will build a voltage divider to lower the Vin voltage. When the gate voltage is at a lower potential, the P-channel mosfets (DCin) will enable and then pass the voltage onto the main logic board.
As a quick test, now that this dual mosfet is removed, ground the gate pin of the DCin mosfets. This will force the DCin mosfets to enable.
Yes. Agree that this component is likely defective.
You can check the same resistance values on the component while it is on your work table.
Check the resistance between:
source & drain
source & gate
gate & drain
There are 2 such mosfets inside this single package so check both.
A low resistance on any of the above checks means the mosfet is defective.
With the logic '1' = ~3v on the gate on a 2N7002, the mosfet should be ON.
When the mosfet is ON, the lower resistor on the above portion of the schematic will build a voltage divider to lower the Vin voltage. When the gate voltage is at a lower potential, the P-channel mosfets (DCin) will enable and then pass the voltage onto the main logic board.
As a quick test, now that this dual mosfet is removed, ground the gate pin of the DCin mosfets. This will force the DCin mosfets to enable.
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