Another Dell not charging / PS_ID issue

[AdrenalinTL]

Hi,

This board is driving me crazy. So it's the usual AC Adaptor not detected in BIOS etc. Battery doesnt charge.

Got a new charging pin, original Dell charger that works, another battery that also works. Still have an issue.

Problem is I am very new to this so I need a very laymans way of explaining to me what I should check.

Thanks Guys

Edit : Board is a LA-J081P

[mon2]

The power adapter is detected by the PSID center pin. This pin communicates over the 1-wire protocol.

Attach the power adapter and carefully measure the voltage to ground of the ferrite bead at PL3. This is an EMI (noise) filter. Check both sides of this part. We are checking if there is a voltage to power the 1-wire ID chip that is buried inside of the power adapter.

[AdrenalinTL]

Thanks.

Bear with me pls as I said I am very new to this. Took me 15min to find PL3

Hope this is PL3 I am measuring.

Top Top left - 0
Top right - 0.26
Bottom - 2.2

[mon2]

See attached. The part that was measured is the transistor PQ2 (3 leaded part).

We are interested in the 2 leaded part to the left which is PL3.

Also interested in the measurements of the voltage to ground of the transistor that is at the top left of the ic @ PQ1.

Post each measurement.

[AdrenalinTL]

Thank you.

Both measure 3.32

[mon2]

Assuming these are the measurements are for each side of the PL3 component (not the PQ1 mosfet = 3 leads).

These are good measurements. Suspecting at this time that the fault is more of a physical one between this component and the center pin that is used by the power adapter.

Remove all power -> meter in DIODE mode. Short your meter probes and the meter will tone beep. Then use one of the meter probes and place onto either side of this PL3 component. Other meter probe to the power adapter connector that is on the logic board. Continue to probe around till you hear a tone beep. You are checking that the PCB copper trace is reaching the power adapter connector. Very likely it is.

Next to inspect is the center needle like pin on the power adapter and also the female side for this needle pin. Sometimes, the power adapter connector on the logic board is not tight enough to mate with the power adapter. Do a visual inspection of the above details first. If this PL3 part is not able to connect to the power adapter center pin, the power adapter specs cannot be extracted over the 1-wire communication line. Be 100% sure the power adapter you have is original and is known good DELL type. Other brands are not to be trusted.

[AdrenalinTL]

Ok, only pin number 4 beeps with 1 on the resistor and the others on the power DC IN adaptor... presume that's what you are referring to.(PJPDC1)
Charger is 100% dell 65W original.

[mon2]

According to the schematics, it should tone beep at pin # 4 of the power adapter. Confirm this detail. The part @ PL3 is a ferrite bead (not resistor) - this part acts like a resistor at high frequencies to offer resistance to block out electromagnetic noise = 'EMI filter' function. At low frequencies, the part has a lower resistance to permit the passing through of the signals.

Locate the mosfet (is like a transistor) @ PQ1 = 3 leads.

We are interested in the 'S' pin (noted with the arrow of the attached diagram) = SOURCE pin. Remove all power. Meter in diode mode. One meter probe on the SOURCE pin. Other meter probe on the nearby black tiny 2 leaded parts = resistors. We are hunting for the 33 ohm resistor that should tone beep once it is found.

Once you believe you have found the 33R = 33 ohm resistor, switch the meter to resistance mode. Then still with no power, one meter on one side of the 33R resistor (or can even be on the source pin of the PQ1 mosfet) and other meter lead on the other side of the 33R resistor.

What is the resistance of this 33R resistor in ohms?






Post your measurements.

[AdrenalinTL]

Holy moly....
So right after posting, I inspected the charger. The middle pin was completely bent to one side. Hence it not going all the way in, hence the issues I have been facing for WEEKS now.

I have verified the charging now, BIOS picks the charger up, CPU is running at full speed, and the bttery is actually going up in %.
Thank you for your help and when I sell this laptop, I am going to make sure to donate to this website because you guys absolutely rock.

[fauzanmint]

Is any idea to disable ps_id ?

[mon2]

Short answer - no.

Long answer - a sub $1 usd microcontroller could be used to emulate the expected handshake over this 1-wire interface to allow for the normal boot. However, then how can one guarantee that the power adapter is truly able to meet the power rating as required? Such emulation parts can be risky to use since they can be a possible bypass tool.

[mcplslg123]

Is any idea to disable ps_id ?

The idea itself is doomed