Lenovo ThinkPad E531 no 3v or 5v standby

[mattpd]

Motherboard will not power on.

Missing 3valw and 5valw

No VIN or EN signals on TPS51225 chip (page 48)

VIN is short to ground (3.0 ohm). TPS removed and it's still short on VIN pad.

Next steps?

[meritosari]

Re: Lenovo ThinkPad E531 no 3v or 5v standby

please try remove power jumper/PJ one by one to isolate B+ that has shorted, i.e PJ401 then decide what pins still shorted pin#1 or pin#2 after you remove it.

[mattpd]

Re: Lenovo ThinkPad E531 no 3v or 5v standby

please try remove power jumper/PJ one by one to isolate B+ that has shorted, i.e PJ401 then decide what pins still shorted pin#1 or pin#2 after you remove it.

Thanks. Found a shorted FET in the CPU VCORE area.