Hi I have 2 Dell Latitude E6540,
1 had short circuit which I fixed but both say charger unknown in bios and on post. Charger is original and confirmed good on a 3rd same model which also had a short which I repaired, this sees the charger as 90w.
1 is La-9411p and the other is La-9413p.
I have checked the PS_ID signal on Scope and both are present to KBC (mec5075).

Is there a common issue with this model ?.
Thanks

Hey.
Try to reset the BIOS using JTAG_RST.
Multicontroller KBC mec5075 has its own firmware. Maybe you need to flash it.

Hi yes I cannot find dump of Mec for the la-9413p.