For the past few days on I've been experiencing an odd problem on my main Windows 7 (64 bit) box in that the machine doesn't reliably wake from sleep. (Specifically, the hard drives/fans, etc. sound like they're spinning up fine, but no video output occurs and the system just sits there whirring away.)
If I power off by holding down the power button for three seconds and then start up again, the machine then goes into resume mode and eventually all is well. I've tried disabling hybrid mode and running
"powercfg.exe -h on" as per this existing question/answer, but this didn't make any difference.
The machine has been fine for 6+ months, I've installed no hardware, software or made any configuration changes and there have been no software updates since the 13th (nearly two weeks ago).
As such, I'm stumped. Any suggestions?