Dell Inspiron 15 Gaming 7567 LA-D993P Rev1.0 Watt Problem

[ilkysmt]

When the customer brought the device, only the charging port was broken. The charging port was replaced, and the PR114 33-ohm resistor, which transmits the psid voltage, broke. However, the device then gave a low-wattage warning and reduced performance with the original 130W charger. When I tried it with another customer's 240W charger, the warning disappeared, and the device functioned properly.

I opened the original charger and checked the internal ID IC. There was no problem. Then, just to be sure, I ordered the 330W DS2501 IC. When it arrived, I tried it again, and the warning was the same.

I then went and tried it with a new 130W charger, and the result was the same. I tried it with a 180W charger, and the result was the same.

What I don't understand is how the device worked fine with the 240W charger, but not with the original charger.

Should I try finding a 240W charger or is there another method?

[mon2]

What is the voltage to ground of the same ps_id pin on the adapter connector on the logic board?

Remove all power, meter in resistance mode. Measure the resistance to ground of the same line. Post all measurements.

[ilkysmt]

The value between the id and ground in the charging socket is 10k ohm

[mon2]

See attached for the PS_ID circuit of your board.

Update: Remove all power and do review the resistance across PL106 ferrite bead. This resistance should be ~0R ohms - if not, replace it. If required, you can bridge this part for quick testing.

Do you have a part @ PR102 is a jumper trace on the PCB? If a part, check the resistance here across the contacts.

With such a high resistance to ground of the PS_ID, we know that the ESD diode @ PD100 is not defective. With a high enough surge, PD100 will be shorted and present a much lower resistance.

Other points of failure are PQ100 and PR114 = often are 33R ohms here but they do get damaged.

Consider to replace PQ100 or review the pinout and bypass this crowbar mosfet. If a high enough voltage is present on the adapter that is beyond the spec of the laptop, the voltage divider resistors on the gate of PQ101 will present a high voltage to enable PQ101 which in turn will disable the mosfet @ PQ100 to ideally save the logic board from damage.

As a quick test, you can remove PQ100 and short the source & drain pins of this SOT-23 package. Be sure to review the datasheet to short out the proper pins or simply replace this part with a fresh one and test again.

[ilkysmt]

According to my measurements, 1.95v is coming to the 36th pin of the IO IC. Actually, I'm thinking about this now. This device worked normally with a 240W adapter and the ID voltage I measured with that adapter was around 1.6. I wonder if changing the resistor and making the ID voltage 1.6 will solve my problem?

[mon2]

The communication integrity matters more than the voltage. This line is a 1-wire uart that transfers packets of data from adapter to motherboard. Review each part on this line from connector to the EC pin. Simple to bypass the mosfet and bridge parts for a quick test.

[ilkysmt]

I measured and looked at everything but I didn't understand what was going on. I'm thinking of buying a 240W adapter and delivering it to the customer. The voltage reaches the IO integrated circuit.

[mon2]

It is a gaming laptop so perhaps this power pig demands the use of a 240W adapter?

[ilkysmt]

The original charger is 130w. As a last resort, I will find a 240w adapter and try it. If it works, I will buy it.