Surface Pro 4 - Screen won't wake from sleep

Dang, it went to hibernate, forgot to check that. I'll have to disable hibernate and try again.

Thanks dkb1898 and again Mike1098 for your inputs.  Dkb1898, would you mind showing us your sleepstudy mW’s and “High, Moderate, Low” system levels in you sleep studies (of course not using Mike1098’s USB workaround).  (as a reminder, under cmd prompt, "powercfg /sleepstudy").  Also, if you can, would you mind testing a scenario where you fully charge to 100% and leave plugged in for an extended period (say overnight) then unplug, then put to sleep under battery power and then wait 10 minutes before waking (if woke, wait another 10 minutes and wake again for a 2^nd^ test)? 

Just so you know, this scenario consistently caused NoWake for a few days, either in the 1st wake attempt or 2nd,  then it stopped happening.  It then only occasionally caused a NoWake in my SP4.   Sometimes, associated with that occasional NoWake, I had also changed wifi signals and in each case these NoWake scenarios had a 6+ hour full charge.  If I did a full charge in some short interval, say under 3 hours, I would not have any issues waking (but those scenarios used the same wifi signal).  I seem to have found a very specific NoWake scenario in my SP4 and it has something to do with miss information after a full charge and possibly combined with changing wifi signals while in sleep.  No doubt frustrating.

In the ‘test for wake after full charge’ scenario, I would typically use <20mW’s per hour (and often 0mW’s) as well as Green-Low System Activity.  These results and the fact that my NoWake only occurs when the sleep usage is likely low suggests to me that there is a link.  After a while, my sleep uses consistent energy per hour and it has yet to have a NoWake after the 4/19 update but only after I get passed the initial wakes from 100% battery.

Some more info I remember that may or may not be relevant. I first encountered the failure to wake (I'll call it FTW) bug way back when I got an Asus T100 using Windows 8/8.1. Asus was quick to release a firmware update though that actually fixed the problem. I wish I knew what they changed to make it work, the USB settings are still at default. I've upgraded this unit to Windows 10 and it still doesn't have any sleep issues.

I encountered FTW again using a Nokia Lumia 2025 Windows RT tablet. No update came from Nokia or Microsoft so this is were I first used the USB hub workaround. I have a 7 year old Toshiba Satellite that has also been upgraded to windows 10 and has never ever had a sleep issue, neither did other standard type laptops I've seen. That cheap-o Toshiba has actually been one of my most reliable computers ever and still gets used when my SB is acting up.

In the back of my mind I've always felt that it has something to do with detachable keyboards. I have no evidence to back this up nor the knowledge required to do so, but it's always been my hunch.

I don't know if this helps anyone, just putting it out there.

In the back of my mind I've always felt that it has something to do with detachable keyboards. I have no evidence to back this up nor the knowledge required to do so, but it's always been my hunch.

I don't know if this helps anyone, just putting it out there.

I had a funny feeling the detachable keyboard could have been a culprit as well and posted strange observation on my SP4 when I did a full reboot and closed the lid (with the type cover). It would turn off the screen when the setting was to "Do nothing" and also when the type cover was very close the closing, it would also flash up the Auto Rotate option. However I cannot tell why this occurred and can't link it back to why the USB workaround appear to make the no wake issue disappear.