I have recently discovered, but am not proficient enough with the 'powerconfig /sleepstudy' troubleshooting tool and Event Viewer seems like it could be handy, but I haven't been effective with delving into the outputs. I have tried all the usual tricks of turning off Hybrid sleep, turning on/off hibernate, making sure all the drivers are up to date - I've gone direct to the Intel tool to scan my computer and found many more drivers that Lenovo's driver update tool didn't identify, and installed those too. Therefore, this seems like a problem that evolved all of a sudden. Prior to this, only the wake-from-sleep case was occurring once or twice every ~10 times I put it to sleep, but hard shut-down and turning it back on worked. This problem is 100% repeatable as of a week ago. To get back to Windows, I have to do hold down power for 20 seconds to turn off and drain power, or else use the Novo button. Then I hard shut-down by holding the power button for a few seconds, and try to turn it back on: The power light goes on and the keyboard lights up for a moment, but the screen never reacts. Clicking the power button gives no reaction - power light still varies on and off as if it's in sleep keyboard and mouse get no reaction. If I put the computer to sleep in any way - lid close, short click of the power button, Start>Power>Sleep, etc., then it goes to sleep and will not wake no matter the input. I think the problem can be pin-pointed back to a driver or some other error, and I'm looking for some help. I know it's backwards to replace hardware before troubleshooting software, but Lenovo tech support made a mistake and are now 'troubleshooting' the software by jumping to a fresh windows install.

The hardware repair did not fix the problem.

I've now had my motherboard exchanged on my Lenovo C940, under warranty, after this problem came up just over a week ago.

My computer is stuck in sleep mode