OK, I have an i5-6600K rig. I'm currently running a Seasonic PSU, which is allegedly "Haswell Ready", (and thus "Skylake ready"), with respect to the new Intel deep sleep, very low power standby mode. The trouble is, if you ignore the machine long enough while it's in standby, it won' wake up, (no signal to monitor), by the normal "press a key, any key" method, or with the mouse or keyboard. To get the machine to "wake up", you must do a "forced shut down", by holding the power switch in, until it goes dead. Then, after pressing the power again, the machine reboots, and resumes Windows. This is tacitly, "resume from hibernation", or "resume from suspend to HDD", not S-3, "resume from RAM". (Also, it's not the "hybrid sleep mode", it's supposed to be). One other consideration, a GTX-1050 ti is installed, with a reasonably up to date driver.. This behavior has only recently begun, and my question is, whether the PSU bad, is the after-market video card and driver provoking it or, is this just quirky behavior based on Intel's deep sleep, low power standby modes, which I'll just have to learn to accept?. Arguably, an estimate of this condition arising, (pardon the pun), is maybe 6 or more hours in standby. In less time, the machine will wake normally.