Lenovo yoga 920 no power

[iveqy]

Hi,
I've a Yoga 920（DYG60 NM-B291 rev：1.0 that no longer charges. I'm pretty new into electronic repairs and don't really know where to start. But I (think?) I've made some progress.

The charging won't step up its current (see attached photo) and I've identified that there seems to be a short over the circled resistors.

There's some threads about the yoga 920 here, but I haven't had any success reading them.

[mcplslg123]

Re: Lenovo yoga 920 no power

Those are capacitors and not resistors as far as my eyes can see.

[iveqy]

Re: Lenovo yoga 920 no power

@mcplslg123 that might very well be true.

I'm stuck and need a way forward in how to proceed looking for errors here. What would be the first step to diagnose this?

[mon2]

Re: Lenovo yoga 920 no power

Both, the schematic and boardview files are available on this forum for this logic board.

Using the boardview file, identify which caps are appearing to be shorted.

Post the screen portions of each file here for a review.

With no power and no battery, these caps have a low resistance to ground? What are the exact readings?

[iveqy]

Re: Lenovo yoga 920 no power

thanks, it's c405, c406, c408 that seems shorted.

The exact reading for the caps to the ground is 0.4 Ohm on one side and 0.7 Ohm on the other side (all three have the same).

Attaching screenshots of the relevant areas

[mon2]

Re: Lenovo yoga 920 no power

See attached. Locate and lift up one leg of the coil / inductor @ L24.

This is to isolate the group of caps and the target IC voltage pin.

After lifting up the leg, check if the low resistance to ground (short) still remains or not.

Post the resistance readings.

[iveqy]

Re: Lenovo yoga 920 no power

thanks. Unfortunately I'm lacking the equipment to do that right now. Will try to borrow it tomorrow.