HP Pavilion X360 burned mosfet

[Roll]

Hi, I have a HP Pavilion x360 - 15-dq0007nc (just about 26 months old) with burned mosfet. Sadly I didn't found any boardview or schematic for this model, so I need your help with this.

The mosfet right next to it is probably SM3319NSQA N-channel.
The burned one is connected to a Sic634 pin 8-11 "Power stage input voltage. Drain of high-side MOSFET" So it should be a P-channel? Can you help me with finding the right replacement?

Also I measured about 15 ohms to the ground on the coil. But I didn't remove the burned stuff yet - it will wait until monday when I can use the microscope for this.

Thanks for your help

[mon2]

Re: HP Pavilion X360 burned mosfet

Hi. No, the high side mosfet will be much like your low side mosfet, both being N-channel.

Personally, would use a different brand than the one on the board considering it has failed already.

See attached on the datasheet for the Richtek part which is showing in your pix.

This device is using the MOSFET driver you have mentioned and then each mosfet driver is linked to a HIGH SIDE and a LOW SIDE mosfet to switch out the desired voltage which is very high in current (pig CPUs).

Given that each SIC634 mosfet driver is driving 2 x mosfets - there must be more mosfets that we cannot see - perhaps on the bottom side of the logic board ? Are they ok or did they also fail ?

Q: How did you get here ? Liquid damage ? Just failed one day upon power up ??

[piernov]

Re: HP Pavilion X360 burned mosfet

Using a different brand won't make the circuit more reliable. Specs are important for a low voltage/high current switching converter so it's not necessarily easy to find a proper replacement.
The SIC634 is a integrated power stage meaning that it's a single chip with MOSFET driver + high/low-side MOSFETs. Unrelated to the issue here since it's for VCore and the issue is on VCCSA.
In any case the CPU is probably dead since VCCSA high-side MOSFET shorted and sent 19V to it.

[Roll]

Re: HP Pavilion X360 burned mosfet

The laptop just failed to boot. Owner said it did try to boot once more after, but now it just turns on the power light and nothing happens. It looks extremely clean, owner said he didn't use it very often. I actually didn't even remove the board from the body, so I'm not sure how the other side looks like. This blown fet was the first thing I noticed, I didn't investigate more.

I can try to replace them with better ones, but I think the one was just crap from the factory.

Are you sure it is VCCSA line? Any way to check if the CPU is dead?

Also when I try to power it up, the other fet gets burning hot

[Stevedb]

Re: HP Pavilion X360 burned mosfet

Why do you try to power it up so much. Just replace the mosfet. How many times you power device are less chanchange to safe the board. Never power up a board with burned component.

[Roll]

Re: HP Pavilion X360 burned mosfet

The board was left plugged in for a few days by the owner. If there is some damage, it probably already happened.

Anyway I removed both fets and measured about 10 ohms to the ground on the coil. That's normal right? I could not source the parts locally, so I have to wait for them to arrive from China.

If it will not do anything after replacement, CPU's dead right?

[mcplslg123]

Re: HP Pavilion X360 burned mosfet

Its waste of money and time to replace those components. High side mosfet shorted on VCCSA/VCORE/GFX=cpu gone

[Roll]

Re: HP Pavilion X360 burned mosfet

Parts are $5, board is $400. So I will at least try it. Even though I don't give it much hope