Dell Latitude 5440 no power on

[imedbox]

ihave the same probleme the labtop want charge with the power supply! my bat is decharged then i can test it with battry it power on!
i got this after flash bios "XM25QH256C" for removing admin password,i revert to the original then not charge or power on, befor it power on and chargin!
Any Help !

her link for Boardview and the Schematic
Dell Latitude 5440
bios version : 1.12.20
MTHERBOARD : IDB40 LA-M401P Rev:1.0(A00) 2023-11-10

https://www.transfernow.net/dl/20250721QpvcJ0UG

[mon2]

Which charger are you using? What is the voltage output when you mate with this logic board? If all is well and using USB-C as the power adapter, you should see 20V.

[imedbox]

Which charger are you using? What is the voltage output when you mate with this logic board? If all is well and using USB-C as the power adapter, you should see 20V.

i User the original power sup and i test the voltage on "CT18" get 5v! it shood be +20 the "PU3" get 5v ! shood be +20
as the shemat PR43/PR46 HAVE 0.116V

[imedbox]

update...

[mon2]

Now switch to another USB port with this adapter. Measure these points again and you should observe the voltage will shift to the next resistor.

The adapter style you are using is the USB-C style.

What is the voltage to ground of +RTC_CELL?

The power delivery from the external USB-C adapter will be 20V only if the power delivery controller (UT3) is properly negotiating this request. By power on default, the voltage is correct @ 5v. After a proper handshake over the CC1 / CC2 lines on the USB-C connector, only then will a USB-C adapter offer the 20V to power the laptop and charge the battery.

Test the other USB-C ports and also suggested to rotate the USB-C connector by 180 degrees to use the bottom side of the USB-C blade connector. That is, CC1 is on the top half / CC2 is on the bottom half of the connector blade. We are wanting to test each side to see if any of these are capable of supporting the 20v voltage.

In general, hate the USB-C interface. Suggest to unplug from the wall -> plug in the adapter to your laptop -> now plug into the wall to power up the adapter. This sequence of events will limit / prevent any possible cross shorts of the dainty USB-C connector traces that often kills the power delivery controllers.

[imedbox]

yes the voltage will shift to the next resistor 5v. even rotate the USB-C
i always use my original USB-C charger.
it seem serious issues i give up must go to repair shop fo fixing. i think it the power delivery controllers ded