08-01-2019 09:37 PM
C930 does not sleep when closing lid. Instead Tablet Mode is activated when lid is open <=30 degrees. Default Power settings (sleep when lid closed), Yoga Mode Control is installed (latest version), behaviour persists after resetting windows (tried closing lid in setup screen itself without touching anything).
I have recently purchased and received a Yoga C930 13lKB 81C4 directly from Lenovo. After setting up the device, I used it as a laptop for several days. The lid when closed put the computer to sleep, as expected. Afterwards, the wifi card in my c930 fails to connect to the network every time the computer wakes from sleep (common issue, installing latest drivers seems to fix issue). I then installed drivers for Wifi, Bluetooth, BIOS updates (refused to install since I was already on the latest BIOS version) and the Intel Management Engine Firmware (I thought this was for the Spectre/Meltdown problem, turns out it wasn't). Wifi and Bluetooth installed without problems, same with Firmware driver (although the BIOS seemed to "crash" and restart, then windows loaded normally). At around the same time, I decided to use the tablet mode on the c930. After this moment, closing the lid does not put the computer to sleep. Lenovo Vantage and Windows update had no new drivers, resetting all power options had no effect. Having the computer in tablet mode is problematic as this mode is also initiated when connecting to external monitors and closing the lid, as the computer "thinks" it has been rotated 360 degrees, hence crippling the computer when it should behave as a normal laptop. I then reset windows without keeping any personal files with no effect.
I suspect there are several reasons for this behaviour:
-Broken Yoga Mode Control driver for handling the behaviour of the lid
-Installing the Intel Management Engine Firmware 11.8 somehow broke the ACPI Lid driver? (not sure if it was a good idea to install this firmware, or if it was necessary)
-Corrupt OS install
-Worst case scenario: Hinge is defective and needs to be exchanged (although I have never seen this in reviews)
If anyone has similar issues/experiences with their Yoga computers, any suggestions would be appreciated. I was excited to use this machine as my first laptop computer, however this issue could be a premature sign of hinge failiure, which does not instill confidence about the durability of this device, as I plan to use it as an iPad pdf reading replacement and a windows laptop.
Solved! Go to Solution.
08-11-2019 02:08 PM
(Found this out on Aug 4 but forgot to update my post)
I've done further testing on my C930 and after running the "sensors test" through Lenovo Diagnostics the lid sensor test reported a failiure with the approximated message "lid closure not detected, the lid sensor is not working well". In summary the diagnostics software failed to detect the lid closure. As a side note, it also said the accelerometer used for tablet rotation was providing incorrect values when performing the accelerometer interactive test, not sure if that was user error.
Afterwards, I discovered from a fluke accident that the lid sensor was definately broken on the device.
When showing the c930 to a friend one day, I closed the laptop expecting it to not sleep, used my left hand to singlehandedly grip the computer hard on the left edge near the hinge with the Lenovo logo. I held the computer with the right side vertically upwards, and the pressure on the hinge caused it to sleep. When opening the lid the computer wakes from sleep again.
Clearly, this sounds like a hardware issue with a stuck switch that only triggers with extreme preasure. However, I've discovered that the computer only sleeps when held in a vertical position after multiple attempts, so perhaps the accelerometer readings is combined with the lid sensor to determine whether laptop mode/tablet mode is active? I am unsure whether this implementation exists, therefore I hope it is simply a faulty hinge sensor.
The computer has been sent for repair, support seemed to understand the issue rather quickly (perhaps it is a common defect) and hopefully the lid sensor would be fixed.