Lenovo Thinkpad W540 No Screen

[handyfreax]

Hello,
Got a W540 with no display, can't say what happened to it.
Board LKM-1 WS MB 12291-2 48.4L013.021
CPU i7
Bios is not the Problem, have flashed.
Power on and off is Working.

GPUVCORE_CURRENT_VINT20 U120 0V
R833 0V
VINT20 18,74V / 18,50V Normaly 20v

CPUCORE_ON on U101 3,29V

VCCCPUCORE 17,9V think normaly is 20V

VINT20_GPUVCORE_PWR- 18,62V

VINT20 on U120 18,62V

After Change U120
VINT20_GPUVCORE_PWR- 20V
VINT20 20V

GPUVCORE_CURRENT_VINT20 0,02V
on R833
GPUVCORE_CURRENT_VINT20 0,02V
GPUVCORE_CURRENT_VINT20_EC 0,02V

C8321 GPUVCORE_CURRENT_VINT20_EC 0,02V

And now I don't know what to do, my suspicion lies with the U23.
But I haven't found a signal either to see if it doesn't arrive before that?
Someone a tip for me?
.

[mon2]

Re: Lenovo Thinkpad W540 No Screen

Vcccpucore 17,9v

Sure? Usually the cpu rail is around 1v0 or less. Need to check against the schematics.

[handyfreax]

Re: Lenovo Thinkpad W540 No Screen

Sorry my misstake is 1,79V