Hi all! I have an odd problem that has perplexed me for a little while now. In our environment, we have several SFF Precision 3460s. The rest of our environment is a mix of Dell workstations, SFF  Precision 3450, 3430s, 3431s, and Dell pro max slim shadys. 

The problem: We find these machines drop into a state akin to a sleeping beauty. The power light indicator is on, but the OS is dead and there is no activity. WOL, tapping the keyboard, short pressing the power button does nothing. We have to long press the power button until it turns off. Starting up Windows, there is nothing in the logs, events just fall of a cliff as if the power had been cut. This issue usually happens when a user locks their windows sessions or disconnects remotely. One of my users would experience this every Monday (user does not work weekends) until I swapped her computer for a 3450. 

What have we done? BIOS and driver updates galore via Command Update. These machines are up to date on Windows updates as well. BIOS power settings, we disable S4, S5 sleep and allow S3. I may be wrong but being that I have a mixed environment and this is the only model that exhibits this, I feel it's a hardware issue. Has anyone seen this? Any suggestions?