MOSFETs burned in 19V line

[Öğretmen27]

19V is not supplied with whichever IC is removed on the laptop motherboard.
I made a mistake.
ISL62771 was burned.
I took out ISL62771.
I gave 19V, the mosfets burned
Which IC is idle on the motherboard, 19V is not supplied.
Can I request some detail information?

[ktmmotocross]

Re: MOSFETs burned in 19V line

.

[SMDFlea]

Re: MOSFETs burned in 19V line

Laptop model number, motherboard part number ? .Is there a schematic for it ?

[Öğretmen27]

Re: MOSFETs burned in 19V line

Thank you.
I had removed ISL62671. When I gave 19 V, the mosfets burned. What is the reason of this?

[Öğretmen27]

Re: MOSFETs burned in 19V line

Lenovo g50-70 NM-A271

[SMDFlea]

Re: MOSFETs burned in 19V line

Schematic https://www.badcaps.net/forum/attach...7&d=1454346973

[SMDFlea]

Re: MOSFETs burned in 19V line

Which mosfets burned ?

[Öğretmen27]

Re: MOSFETs burned in 19V line

PQ302, PQ991 and PQ992.

[piernov]

Re: MOSFETs burned in 19V line

Why do people still randomly inject 19V (and recommend others to do so…) when it's been said many, many times that this can definitely kill your CPU/GPU/PCH if high-side MOSFET is shorted… And if you inject right away 19V at the wrong place you're also sure to burn half the components on the board.

Always measure exact resistance to ground to see if there's a possibility of high-side MOSFET short, and always start with 1V and check if any large BGA is warming up.

EDIT: it's also been said many times that you should never push power into the board with a buck controller/MOSFET driver removed. The MOSFET gates will be floating and get enough charge to randomly turn on and kill something after them.

[ktmmotocross]

Re: MOSFETs burned in 19V line

Why do people still randomly inject 19V (and recommend others to do so…) when it's been said many, many times that this can definitely kill your CPU/GPU/PCH if high-side MOSFET is shorted… And if you inject right away 19V at the wrong place you're also sure to burn half the components on the board.

Always measure exact resistance to ground to see if there's a possibility of high-side MOSFET short, and always start with 1V and check if any large BGA is warming up.

EDIT: it's also been said many times that you should never push power into the board with a buck controller/MOSFET driver removed. The MOSFET gates will be floating and get enough charge to randomly turn on and kill something after them.

AMEN brother

but if he allready inject 19V it is done.

[Öğretmen27]

Re: MOSFETs burned in 19V line

Why do people still randomly inject 19V (and recommend others to do so…) when it's been said many, many times that this can definitely kill your CPU/GPU/PCH if high-side MOSFET is shorted… And if you inject right away 19V at the wrong place you're also sure to burn half the components on the board.

Always measure exact resistance to ground to see if there's a possibility of high-side MOSFET short, and always start with 1V and check if any large BGA is warming up.

EDIT: it's also been said many times that you should never push power into the board with a buck controller/MOSFET driver removed. The MOSFET gates will be floating and get enough charge to randomly turn on and kill something after them.

Thank you so much.
Is there a topic I can follow?
Link please.

[mcplslg123]

Re: MOSFETs burned in 19V line

I think this mb has got serious damage due to your costly mistake and very likely repair is not viable