When it goes to s;eep and i try to bring it back

you can't run 2 different inputs at the same time. VGA takes prescedence.

You might try a new video card and new VGA Cable from computer to Monitor. That is the easiest tests.

Let me know if solved.

Check if you VGA is properly settled in the PCI slot. Try to take it out, clean the slot for dust.
If that doesn't help, it is well possible that you VGA is not working any more.

Do you have the correct driver loaded? Are you using DVI output on the computer? Is there a VGA output? If so, try using a VGA cable while you troubleshoot the video issue.

I see that this monitor has a DVI input, in additon to the VGA input. I suggest getting a suitable cable to use the DVI input, to see if the fault replicates. If it doesn't, you have identified the problem - an issue with the analogue signal processeing circuitry in either the monitor or the computer. The monitor's auto sleep analogue circuitry, for example, may not be sensing a signal, and going to sleep. BTW, if you use a DVI-DVI cable, you avoid the video signal ever going through an analogue stage, and the image will also be purer.

I'm guessing you are using a the VGA input of this monitor (the smaller "D" shaped connector with 15 pins) on the back. If not, and you are using the DVI input (larger white connector), then check your PC video output. I've seen this occur with HP monitors when they accidentally get set to "digital" input. Its easy to set that way (even by mistake), but not as easy to reset to analog (VGA). To do that, you'll need to find someone with a DVI output on their video card. Once you connect to a DVI source, the monitir will come on and stay on. You then need to go into the menues of the monitor, find the setting and change it back to "analog". After you do of course, you won't get an image on your monitor until you reconnect to an "analog" (VGA) source.

Please check whether you are using a DVI (Digital Visual Interface) cable or VGA (Video Graphics Array) cable to the monitor.The monitor will adjust automatically to the requirements of the connected cable.From the question I think you had connected a DVI cable to the monitor.Make sure that there is no loose contact between the ports and the cable.Also make sure that the proper settings on the monitor are done for the DVI cable configuration.

try this

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00061509&cc=us&lc=en&dlc=en&product=3351967

try the link provided

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00061509&cc=us&lc=en&dlc=en&product=3351967

The no input VGA signal just means that the monitor is not receiving anything from the graphic card on the tower. Is the card a digital (DVI) output card? You'll know by the connector, it's white and slightly wider than a standard VGA connector. If so, perhaps the monitor is set to the wrong input?

If that isn't the case, and the computer is using an on-board or built-in graphics controller, you could try resetting the system's CMOS settings by setting the clear-settings jumper on the system board, or simply remove the plug and CMOS battery for a few minutes. Check the computer's documentation on the exact steps to do this.

Hope this helps!