Lenovo Z50-70 shorted +3vs

[RethoricalCheese]

Got a laptop that was shorted simply by plugging in HDMI cable.

Anyway, Found out that +3v3 was showing 0V. Removed PJ303 and it went up to 3v3. Next I removed pins 1,2,3,4 of Q24 and resoldered PJ303. 3v3 is still a nice 3v3, so it is the +3vs that is faulty.

Saw that +3vs is shorted to ground but have not yet figured out where is the culprit.

I tried desoldering pin 11 of IT8586E just to check if that IC is the problem. It isn't. +3VS lane is still shorted but pin 11 is not.

Because it was caused by HDMI, I even tried desoldering Q12 and Q13 cause pins 2 and 3 were shorted. Transistors were in good shape, pads are still shorted.

Any more ideas on what to check or desolder?

https://cdn.badcaps-static.com/pdfs/...30d3a1c5a5.pdf

[fddizon]

Re: Lenovo Z50-70 shorted +3vs

without power to mobo, inject 1v 1amp to 3vs line and feel the parts that is heating up.
that will be the culprit most of the time

[RethoricalCheese]

Re: Lenovo Z50-70 shorted +3vs

Yup, familiar with the method. Will get an IR camera first, should be one in the lab.

[RethoricalCheese]

Re: Lenovo Z50-70 shorted +3vs

Yup, familiar with the method. Will get an IR camera first, should be one in the lab.

GPU heated up. So unrepairable for me.