After perusing this forum, I wonder if there was a recent Windows 7 update that has been causing problems for some HP desktops and displays. My office has a 3500 Microtower desktop running Windows 7 Pro. While Windows 7 Pro is running and in use (as in, not prompted by any user-set power management option), the dual HP displays (via DVI split to VGA) will enter sleep mode ("No Signal", I believe) seemingly randomly/chaotically and without warning. No amount of mouse-waving and keyboard-smashing will wake the displays. The displays will not receive a signal after being turned off then on. Then, not immediately but after some undetermined time, the desktop hard drive light will begin to blink at a consistent 1-second interval (approximate), as though it is stuck in a loop.
My guess, based on both our office's experience and the posts I've read with the same problem (see below for links), is that this update would have become available either November 16 or 17, November 15 at the earliest.
Thank you for your attention to this conundrum!
Aaron
One more piece, not sure if relevant: a user connected remotely in order to monitor the desktop, but detected no problems with the machine. Unfortunately, I was not able to remain with the desktop to see if the displays had shut off at any point during his monitoring.
Links to other forum posts: