Lenovo Y700 BY511 NM-A541 dead

[rupertoos]

Hi.
I have a dead Lenovo Y700 MB: BY511 NM-A541.
When connected to the AC adapter IC's PU802 and PU201, as well as coils PL802 and PL201, are getting really hot, really fast. Any caps that are close to those elements seem to be good (not shorting to ground). After desoldering PU802 and PJ 802, PU201 still gets really hot.

As far as i know, there were problems with Touchpad and USB power before laptop went completly dead.

I have access to bench power supply if needed.

Thanks for any help.

[piernov]

Re: Lenovo Y700 BY511 NM-A541 dead

What's the resistance to ground on PL201?

[rupertoos]

Re: Lenovo Y700 BY511 NM-A541 dead

PL201 is 0.6ohm to ground.

[piernov]

Re: Lenovo Y700 BY511 NM-A541 dead

Ok, full short to ground. You may have a shorted PCH.
Desolder PJ202. Check the resistance to ground on both pads. Inject 1V on the shorted side (should be pin 1 on the schematics), and check which component gets hot, probably the PCH.

[rupertoos]

Re: Lenovo Y700 BY511 NM-A541 dead

Yes after desoldering PJ202 and applying 1V, board draws 3.6A and PCH is getting hot. Will replacing PCH solve my problem or should i just replace whole board?

[piernov]

Re: Lenovo Y700 BY511 NM-A541 dead

If you have a BGA rework station, first remove the PCH and check if the short is gone, check the various voltage going to the PCH (especially +1.0VALW and +3VALW since they are the one shorted) and if everything is fine you can solder a new PCH. If you're lucky that's the only issue.
If you don't have a BGA rework station, just replace the whole board.

[rupertoos]

Re: Lenovo Y700 BY511 NM-A541 dead

Thank you very much for your help. Looks like i'll be replacing whole board.

[lngcs]

Re: Lenovo Y700 BY511 NM-A541 dead

Hi everyone i've got the same problem as rupertoos and found out that if i removed the solder for PJ803 i can see the short to pu802,pl201, pl802 is gone. but one side of pj803 is shorted to ground when pump 1v into that side it drew 5.2 amp and nothing is warm at all not even the pch. could this mean interlayer shorted? anyone solve this ? thanks

[brontobyte]

Re: Lenovo Y700 BY511 NM-A541 dead

Hi everyone! Same problem here, dead Lenovo Y700 BY511 NM-A541
IC PU802 and mosfet PQ104 are hot. i found that the cap right next to ic PU802 is shorted to ground.

[2conexion]

Re: Lenovo Y700 BY511 NM-A541 dead

Hi everyone! Same problem here, dead Lenovo Y700 BY511 NM-A541
IC PU802 and mosfet PQ104 are hot. i found that the cap right next to ic PU802 is shorted to ground.

i have the same problem .... did u fix it?

[revex666]

Re: Lenovo Y700 BY511 NM-A541 dead

Same problem here, Does someone have a .BRD file for me?

[mon2]

Re: Lenovo Y700 BY511 NM-A541 dead

See if the attached works for you.