Dell Vostro LA-L245P Charging not working

[radoslav baca]

Hello everyone,

Description : Dell
Model : Vostro
Serial Number :
Product Number :
CN :
MFD:
Hard disk : NVMe 256GB
CPU: AMD Ryzen YM3250C4T20FG
RAM : DDR4 8GB


MB : GDM54 LA-L245P Rev : 1.0(A00) 2021-07-26

I don't have any other data because there is no data label on the laptop.

I have a problem with my laptop that when I connect the charger, the charging indicator lights up and goes out after 4 seconds. Windows reports charging but does not charge the battery. Can anyone help me with this? I also looked for older threads with this board but couldn't find anything.

[mon2]

Carefully measure the voltage to ground of each pin on the adapter connector. The fault may be due to the PSID pin (PL3) which is used by Dell to gauge the power of the external adapter. If this signal is absent, then the charging will halt.

[radoslav baca]

Carefully measure the voltage to ground of each pin on the adapter connector. The fault may be due to the PSID pin (PL3) which is used by Dell to gauge the power of the external adapter. If this signal is absent, then the charging will halt.

I checked the 3 pin and did not measure any voltage on it

[naze60]

in bios menu show adaptor wattage. example 65w 90w
If it says (unknown), the battery will not be charged

[radoslav baca]

in bios menu show adaptor wattage. example 65w 90w
If it says (unknown), the battery will not be charged

In Bios, it says 65W if I have an adapter connected. If I disconnect it, the 65 W disappears. Even if the charging light goes out, the adapter shows 65 W in the BIOS

[naze60]

So it has nothing to do with the charger
Only the battery remains
Battery replacement

[radoslav baca]

So it has nothing to do with the charger
Only the battery remains
Battery replacement

Thanks

[mcplslg123]

Dont agree completely with post#6. Battery wont charge if charging circuit has issues even if psid is correct. So battery replacement may/may not solve the problem.

If you have a spare battery,try it.Else needs some measurements on charging IC to be sure its not charging circuit.

[piernov]

Always a good idea to try a replacement battery before messing with the mainboard though. A battery is a consumable and it is much more likely to be the problem than the mainboard.

When you are experienced enough you know what to look for and can make an educated guess if it's gonna be a battery or a board problem. When you are not experienced you are more likely to cause more damage by randomly probing and messing around.

That said if the battery is not empty yet and the machine works off of the battery without the AC adapter, but does not charge it when the AC adapter is connected, there's a much higher chance for it to be a mainboard problem.

[radoslav baca]

Unfortunately, the battery is dead, but I can measure circuits if I have documents on what and where to measure

[mon2]

What are the markings on the power adapter? Is it a 60W unit?

Remove all power. Meter in DIODE mode. Red meter probe to ground - yes red probe. Black probe on the PL3 / pin 3 of the power connector (as above). Do not attach the power adapter. Do not attach the battery. We are only checking if this PSID line is shorted due to an ESD or another event. The diode mode measurement will confirm the condition of this signal.

Post the diode mode measurement.

[radoslav baca]

What are the markings on the power adapter? Is it a 60W unit?

Remove all power. Meter in DIODE mode. Red meter probe to ground - yes red probe. Black probe on the PL3 / pin 3 of the power connector (as above). Do not attach the power adapter. Do not attach the battery. We are only checking if this PSID line is shorted due to an ESD or another event. The diode mode measurement will confirm the condition of this signal.

Post the diode mode measurement.

I measured according to your instructions, red pin to ground and black to PL3, and after connecting the charging connector, the state on the measurement in diode mode did not change and showed infinity

[mon2]

Remove all power. Review the DCin mosfets (see attached).

Meter in resistance mode.

Measure the resistance across each of these mosfets:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. Review the above sticky by piernov on charger circuits.

[radoslav baca]

Remove all power. Review the DCin mosfets (see attached).

Meter in resistance mode.

Measure the resistance across each of these mosfets:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. Review the above sticky by piernov on charger circuits.

I measured things as you wrote them and here are the results:
PQB 11 source (1-2-3) & drain (5-6-7-8) 503k Ohm
source (1-2-3) & drain (4) 538k Ohm
gate (4) & drain (5-6-7-8) 0L
PQB 12 source (1-2-3) & drain (5-6-7-8) 484k Ohm
source (1-2-3) & drain (4) 538k Ohm
gate (4) & drain (5-6-7-8) 0L

It's just that my laptop works on the battery, but the charging diode lights up and after a few seconds it goes off, and Windows also says that it's charging the battery, but it shows the battery as almost empty.

[mon2]

Attach the power adapter and carefully measure the voltage to ground on each pin of the same Dc-in mosfets.

Measure the voltage to ground of:

source (1-2-3)
gate (4)
drain (5-6-7-8)

of each mosfet. Post each measurement. A full list of the voltages of each pin on the charger IC will also be helpful but start with the mosfets. Be sure your meter probe is sharp enough to probe each pin on the charger IC without shorting as the charger IC is live.

[rogfanther]

In BIOS, can you see the serial number or Service Tag of your notebook ? With that it is possible to look on Dell´s site what is the correct model, and also what would be the correct PSU. Do you have some memory of the machine ever present some message on boot about the power supply / charger ?

[radoslav baca]

Attach the power adapter and carefully measure the voltage to ground on each pin of the same Dc-in mosfets.

Measure the voltage to ground of:

source (1-2-3)
gate (4)
drain (5-6-7-8)

of each mosfet. Post each measurement. A full list of the voltages of each pin on the charger IC will also be helpful but start with the mosfets. Be sure your meter probe is sharp enough to probe each pin on the charger IC without shorting as the charger IC is live.

I just measured each leg separately and here are the measurements:
PQB11:
S1 - 19,79 S2 - 19,79 S3 - 19,79
G - 24,97
D5 - 19,79 D6 - 19,79 D7 - 19,79 D8 - 19,79

PQB12:
S1 - 19,79 S2 - 19,79 S3 - 19,79
G - 24,97
D5 - 19,79 D6 - 19,79 D7 - 19,79 D8 - 19,79

[radoslav baca]

In BIOS, can you see the serial number or Service Tag of your notebook ? With that it is possible to look on Dell´s site what is the correct model, and also what would be the correct PSU. Do you have some memory of the machine ever present some message on boot about the power supply / charger ?

The charger is an original DELL 65W, which is also shown in the BIOS when I checked it. Windows also shows charging, but the indicator does not go up and also the LED diode, which indicates charging from the side, lights up after connecting the charging and goes out after a short time.