HP OMEN g3ba n17p NO POWER

[madjid911]

Hello, this laptop omen 17-A037NF (motherboard DAG3BAMBAH0 REV : H, SN 5CD812BWNM) of mine won't start at all. The charging light is flashing. The battery is charging properly, the 20V is being supplied, the SIO chip is being supplied with 3V3 and 1V76. I have 5V on one coil, but I don't have 3V3 on the other coil. Therefore, the EEPROM chip isn't being powered. I replaced the 3V3 chip (SY8286C awv7YD) with the SY8288B and the JW5068C, but the result is the same.

So I took a closer look at the 3V3 chip. On pin 11 EN, I measured 4V53, Lx pin 6 0V, BYP 3V3, FB 0V, BS 2V9, and VCC 3V3.
I found no short circuit, the coil disconnected to the motherboard is at 7komhs

So, is there a problem with the FB divider?
I'm really not an expert if anyone can help me please

[mon2]

Can you link a schematic (inside the schematic forum only)?

Yes, it appears that the root cause is on the 3v3 buck regulator who is being requested to turn on through the EN pin.

Root cause is that the replacement regulator is not compatible to the original.

See attached.

[madjid911]

Can you link a schematic (inside the schematic forum only)?

Yes, it appears that the root cause is on the 3v3 buck regulator who is being requested to turn on through the EN pin.

Root cause is that the replacement regulator is not compatible to the original.

See attached.

hello, However, I asked chatgpt and he told me it was compatible. I put the original one back, unfortunately I don't have another one, but if FB is at 0v, it may not be the chip that is the problem, right?

[madjid911]

I couldn't find a schematic for this motherboard dag3BAMBAH0 REV H

[SMDFlea]

I replaced the 3V3 chip (SY8286C awv7YD) with the SY8288B and the JW5068C, but the result is the same.

(SY8286C awv7YD) ? AWV*** SY8286BRAC . The JW5068C isn`t compatible.

[madjid911]

Yes, thank you, I ordered the chip, but since I don't have a Feedback, I don't think it's the chip that's damaged.

[mon2]

Feedback will be from an external source and is built upon the Vout voltage being scaled down with a voltage divider using 2 resistors. Often the FB voltage is 0v6. The regulator will dial up or down the Vout voltage to maintain the 0v6 FB voltage.

If you do not have a FB, remove all power and measure the resistance to ground of the FB pin. Compare this value against the schematic values or the parts onboard. If required, carefully flux and remove the FB resistors and measure them out of circuit. Be sure to not lose them. Stuff these values into the online calculators to determine if the values are logical for the power rail. Reference schematics from assorted power supply vendors will offer similar calculators and a table of resistor values. But in summary, if Vout is zero volts then so will the FB pin.

Facing something similar in repairing an A2141 macbook with sudden death. Traced it down the well documented TPS62180 with a blown 'whale' hole on the top surface BUT in this case, we believe the SSD is ok because the SSD rail is normal and ppbus_g3h is not shorted. Nasty regulators.

[madjid911]

I replaced it with an identical part. I received it today. I just replaced it, but I no longer have the same measurements.

On the SIO chip, I have 2V7 and I no longer have the charge indicator.

On the 3V3 chip, on the coil, I have 2V, but I no longer have 5V on the other coil.

[mon2]

1) Do you trust the source for the replacement parts?

2) For any voltage that is lower than normal, remove all power, measure the resistance to ground of that power rail. If the resistance is low, then the voltage will be low / lower than expected.

3) Be sure your soldering is solid and without shorts - flux and reflow if necessary.

4) If available, check the same with a thermal camera. Is the repalcement part heating up?

[madjid911]

the soldering is well done, no short, no overheating on the motherboard, I don't understand either, 21.6kOMS at the coil output

[madjid911]

I unsoldered the coil and I find the 3V3 on the SIO chip, so the new chip must be defective I don't know

[madjid911]

I am surprised, I have the 3V3 at the output of the 3V3 coil but unsoldered, so when I connect it I drop to 2v, something must be wrong yet the resistance at the coil output on the motherboard is good

[madjid911]

I can't find any shorts though, so when the coil is connected we have 2V instead of 3V3

[mon2]

The completion of the circuit is causing the drop in voltage.

Post again which part was replaced. What are the full markings of the original part and the replacement part used onboard here?

Post a clear topside view of the replacement part for a review.

[madjid911]

and I have 0V72 on the track of the good unsoldered on the motherboard it is not normal to have voltage coming from the motherboard on the coil

[madjid911]

the first one is the original one, it's AWV7YD (SY8286CRAC), the second photo is the one I ordered AWW6RI (SY8286CRAC according to the photo on ebay)

[mon2]

These 2 parts are not compatible. The original was SY8286BRAC; the replacement is SY8286CRAC.

See attached.

[madjid911]

Thank you for these details, however I had seen that on Aliexpress the reference AWV7 corresponded to the SY8286CRAC

I will recommend the part then

[mon2]

The Aliexpress store is in error. Trust the silicon mfr's datasheet over the Aliexpress store. There are pinout differences as well - review the LDO rails and their pin location between the 2 models.

[madjid911]

The Aliexpress store is in error. Trust the silicon mfr's datasheet over the Aliexpress store. There are pinout differences as well - review the LDO rails and their pin location between the 2 models.

Yes thank you very much, so I'm waiting for the new chip hoping it works