Hi, kurt person. I have some questions about your issue:
What operating system are you using?
Did you check if the power options in BIOS changed by any chance? What options are enabled? For example Deep S4/S5 or Wake from S5… You may want to reset those settings to default.
Windows 7 Pro. No changes that I noticed. I will take a detailed look and return to default settings. Another symptom I have been experiencing in the last couple of days is a cycling out of sleep mode by itself for extended periods, hours. At night I end up shutting down to avoid having a bright monitor waking us up. I'll reply with any other items I find or discover. Thank you for the reply.
So, this means that it does not wake up by using the keyboard or mouse, right?
I got an idea about the second issue; you may want to pay attention to the time when the system wakes up by itself or check the Windows* Event Log just right after it happens. You will see a Power-Troubleshooter event (ID: 1) that reads like this:
The system has resumed from sleep.
Wake Source: Device - USB Composite Device (I used keyboard)
This way we may have know what triggers the issue.