FX516PR not charging on DC charger (but charging on Type-C)

[pc_okay]

Hello friends,

I have this board not charging with charger, working fine on battery and type-C charger.

Here what if found: my IC chip miss VCC so i follow the line P_CHG_VCC_30 (0V) to P_CHG_VCC_R_30 (0v) and i get 20V A/D_DOCK_IN.
I loose my 20V on the PQ9009, i think it's dead because it's a P-Channel and I get 0V on gate and 20V on source and finally 0V on drain.

Am I right?


Links for shematics and boardview: https://www.badcaps.net/forum/troubl...s-tuf-dash-f15

Please find attach IC voltage and the circuit that i think is problematic.

Thanks !

[mon2]

The measurements are very low for a good mosfet. Replace the part.

As a test, flux and remove this mosfet and then bridge the source / drain pins (2 & 3) to allow for the voltage pass through. The OVP feature will be lost but will be safe as long as the adapter voltage is ~20v or under.

When the mosfet is off the board, test the mosfet in the same way when it is on your work bench. Each posted measurement is too low for a good mosfet.

[mon2]

Remove all power. Measure the resistance across this same mosfet.

Source & drain
source & gate
gate & drain

post each measurement. Yes, it appears that this P-channel mosfet is dead since gate voltage is low enough to enable and allow for the pass through from source / drain pins.

[pc_okay]

Source & drain 30 kOhms
source & gate 300 Ohms
gate & drain 40 kOhms

Thanks.

[mon2]

The measurements are very low for a good mosfet. Replace the part.

As a test, flux and remove this mosfet and then bridge the source / drain pins (2 & 3) to allow for the voltage pass through. The OVP feature will be lost but will be safe as long as the adapter voltage is ~20v or under.

When the mosfet is off the board, test the mosfet in the same way when it is on your work bench. Each posted measurement is too low for a good mosfet.

[pc_okay]

Thanks, i'll change the mofset directly when i'll recieve those mofset.
I don't want to take any risk because the board is actually working with type C... 😁

Hope that will work !

[pc_okay]

So finaly i change the mofset, i plug charger and.... I heard a little "CLICK" oh that's weird !
Charger was still not working... I try with another one and again "CLICK" ok, something defintly wrong ...

I remove the diode and take my measurement and there was a short on the drain ! my bad, i didn't check after removing the mofset.
After replacing the defect caps and the diode (for the 3rd time) everything works perfectly !

Thank you again Mon ! 😃