Hello,
I have a Microsoft Surface Pro 4 (i5, 8 GB) that originaly had a swollen battery and was crashing during Windows install. I replaced the SSD with a new one (from another surface) that had OS installed. As a result of this the Windows booted, but few seconds after the start it went into "Locking" screen and turned off.
Now the "fun" starts:
Upon removal of the motherboard from the case the fault changed:
- When I start the tablet the VCCSA goes to 1.1 V for half a second and shuts off, followed by 1P2V_DUAL going to around 1 V and cutting of as well.
- VCC_CORE also turns briefly to 0.8 V and then shuts off
- VCCGT never shows any voltage
- I checked the resistance to GND of VCCSA, VCC_CORE, VCCGT and all are the same as my working i5 Surface Pro 4.
- There's no backlight, no picture, etc.
My assumptions:
- Based on the power on sequence it seems as if both VCC_CORE and VCCGT should be enabled by the same signal from the EC. It appears as if the EC shuts the power off because of some fault condition though.
Ideally I would like to probe VRM_PWRGN, VCCST_PWRGD, PM_PCH_PWROK and SYS_PWROK to see when exactly the power on sequence stops, but so far I am not able to locate pads that correspond to those signals.
Can anybody please offer any leads to what should I probe/test?
Thanks a lot!
I have a Microsoft Surface Pro 4 (i5, 8 GB) that originaly had a swollen battery and was crashing during Windows install. I replaced the SSD with a new one (from another surface) that had OS installed. As a result of this the Windows booted, but few seconds after the start it went into "Locking" screen and turned off.
Now the "fun" starts:
Upon removal of the motherboard from the case the fault changed:
- When I start the tablet the VCCSA goes to 1.1 V for half a second and shuts off, followed by 1P2V_DUAL going to around 1 V and cutting of as well.
- VCC_CORE also turns briefly to 0.8 V and then shuts off
- VCCGT never shows any voltage
- I checked the resistance to GND of VCCSA, VCC_CORE, VCCGT and all are the same as my working i5 Surface Pro 4.
- There's no backlight, no picture, etc.
My assumptions:
- Based on the power on sequence it seems as if both VCC_CORE and VCCGT should be enabled by the same signal from the EC. It appears as if the EC shuts the power off because of some fault condition though.
Ideally I would like to probe VRM_PWRGN, VCCST_PWRGD, PM_PCH_PWROK and SYS_PWROK to see when exactly the power on sequence stops, but so far I am not able to locate pads that correspond to those signals.
Can anybody please offer any leads to what should I probe/test?
Thanks a lot!
Comment