La-c881p

[riki_22]

Hello everybody,
problem on xps 13 9350 with battery turns on but does not recharge and only with power supply does not turn on.
i found pd300 burnt.
because I found the broken connector with the pins that made contact. Removed PD300 E
fixed the connector
but i can't solve
Please help me

P.S. for me it is a power supply control circuit problem

[riki_22]

Re: La-c881p

I am attaching photos

[Sephir0th]

Re: La-c881p

This is of course an issue around the charging controller.

But you replaced PD300 with the correct part, right? Confirm this first!

Then continue with Voltage measurements at PR300 and PR313 with only Adapter present. Sahre the values. Also check PU300, Pin5 and Pin6 voltage?

[riki_22]

Re: La-c881p

This is of course an issue around the charging controller.

But you replaced PD300 with the correct part, right? Confirm this first!

Then continue with Voltage measurements at PR300 and PR313 with only Adapter present. Sahre the values. Also check PU300, Pin5 and Pin6 voltage?

I don't have a double diode to put on the PD300, but if I don't insert the battery nothing really should happen. I still made the measurements PR313 3.2V
PR300 19.6V
PU300 P5 3.2V and P6 2.8V

can you advise me where to get a pd300 i have many donor motherboards

[Sephir0th]

Re: La-c881p

Measurements of PU300 and PR300 are fine. PR313 too Low (from charger).

It is still working from Battery?

Regarding the replacement, i can't Take Over the job to search for it for you. Compare with datasheets or Just Order a new one. I'm Not 100% Sure about the function of PD300 in the Circuit but could be important and ofc missing could prevent the Board from booting with Adapter.

[riki_22]

Re: La-c881p

Measurements of PU300 and PR300 are fine. PR313 too Low (from charger).

It is still working from Battery?

Regarding the replacement, i can't Take Over the job to search for it for you. Compare with datasheets or Just Order a new one. I'm Not 100% Sure about the function of PD300 in the Circuit but could be important and ofc missing could prevent the Board from booting with Adapter.

With the battery it works.
With the power supply does not turn on and does not recharge, can this be due to the lack of pd302?
and in your opinion pr313 is low because pd302 is missing?

I found CH501H-40PT I can change it with SDMK0340L

[Sephir0th]

Re: La-c881p

This is NVDC Design, and tbh i'm Not so experienced there in Detail, and i wouldn't Try to Power on the Board before replacing PD300, so yes could be.

Also checked PQ303 and PQ304 for internal Short Circuit? Gate voltages of both Mosfets? PR313 Voltage with Only Battery present?

Edit: i believe without this diode PU300 will Not receive Power at Pin 28 in battery Mode. Confirm pls. And Check Pin28 with Only Adapter present too.

[riki_22]

Re: La-c881p

This is NVDC Design, and tbh i'm Not so experienced there in Detail, and i wouldn't Try to Power on the Board before replacing PD300, so yes could be.

Also checked PQ303 and PQ304 for internal Short Circuit? Gate voltages of both Mosfets? PR313 Voltage with Only Battery present?

Edit: i believe without this diode PU300 will Not receive Power at Pin 28 in battery Mode. Confirm pls. And Check Pin28 with Only Adapter present too.

PQ303 and PQ304 are not internally shorted, the gate of PQ303 is 3.6V and of pq304 is 0.36V
in the PR313 with battery the voltage is 7.73V
PIN28 of PU300 with only adapter is 19.6 , with only battery is 7.15v and both 19.6v but it goes out immediately with both. only battery WORK

[mon2]

Re: La-c881p

Do you have the schematics for this logic board? Please post them if you do.

Otherwise, what is the battery charger IC on the board?

[riki_22]

Re: La-c881p

can i change pd300 (SDMK0340L) with RB501V-40?

[riki_22]

Re: La-c881p

Do you have the schematics for this logic board? Please post them if you do.

Otherwise, what is the battery charger IC on the board?

attached the pdf of schematic. the ic is BQ24777

[Sephir0th]

Re: La-c881p

Just added the Schematics in the Schematics section. I Only was a few Seconds to slow...

[Sephir0th]

Re: La-c881p

PQ303 and PQ304 are not internally shorted, the gate of PQ303 is 3.6V and of pq304 is 0.36V
in the PR313 with battery the voltage is 7.73V
PIN28 of PU300 with only adapter is 19.6 , with only battery is 7.15v and both 19.6v but it goes out immediately with both. only battery WORK

Do you have jumpered PD300 Pads?

[riki_22]

Re: La-c881p

do you have jumpered pd300 pads?

no try?

[Sephir0th]

Re: La-c881p

No, i Just Wonder how it is possible that the battery Voltage Receives Pin28. Something seems to be wrong. Either we're working on the wrong component or Schematics don't fit.

[riki_22]

Re: La-c881p

No, i Just Wonder how it is possible that the battery Voltage Receives Pin28. Something seems to be wrong. Either we're working on the wrong component or Schematics don't fit.

it may be that the scheme is a different revision but the problem for me is
missing pd300

[Sephir0th]

Re: La-c881p

Voltages of PQ303 D - G - S when Only Adapter and Only Battery is present?

[mon2]

Re: La-c881p

Remove battery. Connect adapter.

1) voltage on pin 6 (acdet; pu300) ?
2) voltage on pin 17 (pu300) ?
3) voltage on pin 1, pl300? Pin 2, pl300?
4) pl301, pin 1? Pin 2?
5) confirm the nearby diodes are ok (power removed, meter in diode mode). Should conduct in one direction, block in the other).
6) pin 15 voltage of pu300 with adapter only?

[riki_22]

Re: La-c881p

Voltages of PQ303 D - G - S when Only Adapter and Only Battery is present?

Only Adapter in PQ303 D 19.6V S 3.2V G 3.6V

Only Battery in PQ303 D 7.06V S 7.44V G 7.33V

[piernov]

Re: La-c881p

Voltage from battery goes through PQ305 & PQ303 body diode to reach VCC pin of charger IC.
PD300 should be replaced first, not much point troubleshooting further if parts are missing.

You need a Schottky diode of at least 30V reverse voltage and 30mA forward current and the same package. So yes RB501V-40 should be good instead of SDMK0340L

Note that it's possible there is a secondary problem and PD300 will burn again, so keep a few aside in case. It's also possible it's the only problem and replacing it will solve it.