Dell precision 5520 It only starts with the battery disconnected and with the ac power not recognized message

[Fabbrone]

Already replaced adapter, battery and dock connector. If I only connect the adapter with the battery disconnected, it turns on with the message bios adapter not recognized. While if I connect both the battery and the adapter it doesn't turn on. When it turns on only with the adapter and I try to update the bios it tells me to connect the adapter! can being connected. If I connect the battery when it is turned on with the adapter it turns off. Do you have any ideas?

[mon2]

Review the PS_ID pin on the power adapter connector which must reach the EC by the way of a mosfet in the path.

The adapter must be original with PS_ID pin support.

Often the fault is in the mosfet but may be in the power adapter contact pin. Search out numerous cases on this forum with the same fault. Post back with your results and questions.

[Fabbrone]

Sorry I had abandoned it, now I checked and the power supply is original on the psid pin of the adp100 connector there are 3.28V while on the battery 10.7V

[mon2]

What does the BIOS report for the adapter ratings? Still unknown?

Review the center pin of the power adapter.

Remove all power. Measure the resistance across PR903. Confirm this is ~33 ohms.

[Fabbrone]

I confirm that the adapter is not recognized Unfortunately I can't find pr903 ! from PL901 to PSID pin 4 of ADP100 there is 117K

[mon2]

Post clear pics of the areas linked to this power path.

[Fabbrone]

two affected area

[mon2]

Review these areas.

[Fabbrone]

they are traces of glue or dust they are not compromised components

[mon2]

What are the 'LA-****' silk screen markings on your board? This will identify the logic board model.

Found a few schematics that appear to be linked to this 5520 series.

[Fabbrone]

CAM00/01 LA-E331P REV 1.0

[mon2]

Good. What is the resistance across PR102? No power to the board / no battery when checking in resistance mode.

This should be ~33R = 33 ohms.

[Fabbrone]

Oops there is 1,2k !

[mon2]

Either replace this part with a 10-100 ohm resistor or just solder short the pads to bypass this component. Test again after this mod.

[Fabbrone]

Done and left again calmly, the resistance was broken!

[mon2]

Working now? Adapter is recognized?

[Fabbrone]

Yes Great Lun2, it starts normally without message and charges the battery. many thanks