Permanent Sleep Mode on HP2511x with Windows 7

[Taylor19501]

NOTE:  None of the categories listed above matches my problem, but I've selected "Boot Issue" as this will not post without selecting at least one category...I am temporarily using an Alienware desktop computer with Windows 7 64-bit SP1, and an HP 2211x LED monitor. The monitor is connected to the PC with an HDMI cable. Several years ago, the monitor would frequently go into Sleep mode (making it completely unworkable) but I eventually solved the problem. However, I've lost my notes on how to fix this issue & the problem has arisen again. I am quite sure that the ultimate solution to the problem involves changing the Power Management features in the computer itself, but since the monitor will not respond because it goes into sleep mode, I cannot access any of the computer systems. I cannot even access the Windows Start button to shut the computer down. I CAN access the OSD which shows the monitor default setting as HDMI, but when the monitor scans the cable options, it will not select ANY of them and instead it goes into Sleep mode. Because this happened to me often before, I know this has nothing to do with OS updates, GPU, etc. I'd greatly appreciate any help (even keyboard combinations that will allow me to access computer systems). Thanks.