Vostro 3401 strange problem charge

[the Benninger]

if you start the computer with the charger plugged in it charges without problems and everything works as it should
once started, if you happen to disconnect the charger and reconnect it, it stops charging and feeding the computer; it only works with the battery's charge.
This also happens when it is turned off. Do you have any idea where to start looking for this fault? I have already checked the power jack, the cable, and the charger,
but the problem persists.
Dell Vostro 3401
ModelREG P132G
MoBo:FDI55 LA-J081p Rev 1.0

[mon2]

Review what the BIOS reports for the power adapter for both cases.

[the Benninger]

I casually use my charger, it's the same machine I use for work, and both chargers are original 65W. This malfunction is really crazy; I've never seen anything like it.

[the Benninger]

I am currently using the client's charger on my laptop and it works normally.

[mon2]

So both chargers you own fail like the video? The client's charger works with the same laptop even if you unplug & plug? Can you clarify?

[the Benninger]

same thing, going to need the laboardview of this machine and all the information I can get. I'm afraid it's one of those elusive failures that break head. I'm already starting to take values to see where this takes me.

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of the PSID (power supply ID pin) on the DCin connector. You can also measure @ PL3 to ground.

What is the resistance? We are testing if the TVS diode is defective that is used to suppress transients on this communication line.

[the Benninger]

okay PSID to GND = 115k
on PL301 =2050k

[the Benninger]

I try to enlarge the image you show
me and it gets blurry, it's not possible to zoom in.

[the Benninger]

Connecting the multimeter cables gives a different reading on the two components you requested, which are as follows

PSID to GND = 68k
PL301 to GND = 5000k

[mon2]

Measure the resistance from the PSID pin of the DCin connector to each side of PL301. This must be ~0 ohms. If it is not, you are not on PL301 or PL301 is defective.

If you are confident that you are measuring on PL301, then use a piece of wire to bridge and bypass PL301. Then test the resistance again and it should be ~0 ohms. Then test your adapter again.

[the Benninger]

PSID pin on DC in conector to each side of PL301 (RIGHT SIDE124k) (left side 124k)

PL301 its two terminals 0.2hom

[the Benninger]

I made the bridge as you indicated, and at the moment of connecting the charger, I knew something went wrong.

I heard a spark sound and smoke came out of the component above PL301; if I'm not mistaken, it's PU301. I removed the bridge, and now this component overheats, and the computer doesn't turn on now. As we say in my country, we've messed up.

[the Benninger]

For today, we will leave it here.tomorrow we will see what we can resolve.

[mon2]

My very bad. Yes, PL301 is linked to PU301. PL3 is linked to this PSID. Would you have access to SY8286BRAC? If not, Aliexpress or a donor board.

https://articulo.mercadolibre.com.ve...wv5-qfn-20-_JM

[the Benninger]

There is no problem, it was a small misunderstanding, I am not blaming you, do not perceive bad intentions in what you have said, I am more interested in successfully concluding the repair, life is full of stumbling blocks, the important thing is to go through them and learn.
to those that bind us, it will be enough to replace the PU301, I also cannot locate the PL3 on the board, there is no such signaling on mobo
I am already buying the component Sy8286brac (Qfn20)
I would arrive between Thursday and Friday of this week, and I clarify one thing: I am from Venezuela with Spanish roots, currently living in Sao Paulo, Brazil.
Let's move forward, nothing has happened. I'm going to check in the scratch to see if I have any compatible ones i will let you know anything

[mon2]

Thanks. Yes, do replace the defunct PU301. The part is very inexpensive in Asia (lcsc.com is showing only 1 pc @ $0.50 USD + shipping). I believe the same part should be available local to you in Brazil. There is active electronics manufacturing in Sao Paulo.

Can you post clear pics of the power adapter connector from your board? The PL3 should be nearby. This ferrite bead will be in series with the PSID communication line. On the same line will be the TVS diode and then the OVP (over voltage protection) mosfet that triggers if there is too high of a voltage on the communication line. Since the adapter cannot be detected, suspecting the fault is in the PSID line.

[the Benninger]

some information add

[mon2]

Bad boy PL3 is in the attached location.



Attached is the pinout of PQ1 N-channel mosfet.

Remove all power. Meter in resistance mode.

Measure the resistance between

source / drain
source / gate
gate / drain

Post each measurement. We are testing if this mosfet is defective or not.

[mon2]

Another common point of failure is the series resistor @ PR1 = 33R ohms (normal). Often this resistor will be much higher in resistance and raises issues such as yours.

With no power to the board, measure the resistance across PR1 resistor.