Hi Joe. I'm Greg, an installation specialist and 9 year Windows MVP here to help you.
I have seen a couple of cases of Sleep problems lately which were both solved by the standard fixes I will give you.
I will give you all possible fixes for Sleep, based on ten years troubleshooting it almost daily. If you need help performing any step just ask back:
First confirm you have the Sleep options configured correctly as shown here:
https://www.tenforums.com/tutorials/2843-change....
You might want to try Hibernate to succeed Sleep, or use Hibernate in place of Sleep - it's just a deeper sleep that actually powers off because desktop stored in RAM during sleep is written to hard drive hiberfile then powered off.
Most Sleep problems are caused by the Display driver, so try updating yours from the PC or Device maker's Support Downloads web page for your full model number, Serial Number or Dell Service tag. While there make sure you have the latest BIOS, Chipset, Network, Sound, USB and all other drivers by comparing those posted for download with the version and date of the corresponding ones in the Device Manager.
If that doesn't help then in Device Manager on Display device Driver tab choose Roll back, Uninstall (then restart to reinstall) or try another one previously installed at Device Manager>Display adapter>Driver>Update Driver>Browse>Let me pick.
In addition there are steps here to specifically troubleshoot Sleep mode problems: http://www.makeuseof.com/tag/fix-windows-10-sle...
What I do is go into Advanced Power options and set Display and Sleep to 1 minutes, Hibernate to 2 minutes, then after completing each step restart the PC and observe what happens for 3 minutes.
Also did it previously work? Do you have a System Restore point from when it did?http://home.bt.com/tech-gadgets/computing/how-t...
This may have been caused by Windows Updates. Check which Updates were installed right before the problem began, and if necessary uninstall them from Settings > Update & Security > Windows Update > Installed Update History.
You can also try to roll back using System Restore to a point before this began: http://home.bt.com/tech-gadgets/computing/how-t...
Then if an Update reinstalls and causes the same problem uninstall or roll it back again, then immediately hide it using the Hide Updates tool from Method Two here: https://www.askvg.com/fixing-windows-10-automat...
I hope this helps. Feel free to ask back any questions and keep me posted. If you'll wait to rate whether my post helped you, I will keep working with you until it's resolved.
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