No Input Signal, Monitor Going to Sleep

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

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.

try HDMI? also switch ports on video card in case there are 2

When i turn my computer on my monitor keeps saying no vga input and no dvi input then the monitor says going to sleep ..........PLEASE HELP ME!!!

First, make sure the dvi cable is hooked properly to the computer and that the computer's VGA card's dvi output is set to work in the monitor's advance options.

Has this computer/monitor combinatioin ever worked before? Or did the message appear after successful operation of dvi to the monitor?

Perhaps, try to use a vga cable to the lcd monitor to see if that input works.

Good luck on this repair.

If it goes in to sleep mode, that means that the monitor is not getting a signal from the computer.
The things to try (from simplest to most complex) are:

1. Make sure the computer is on and not in "sleep" mode -- press the "Caps Lock" key and see if it lights up the caps-lock light on the keyboard.
2. Make sure the video cable is connected from the computer to the monitor (that the cable hasn't come loose on either end)
3. If your monitor has multiple inputs, make sure it's set to the right (probably analog VGA or DVI) input
4. If your computer has more than one video output (like a laptop with it's internal screen plus the external monitor) then make sure the external monitor is enabled

If none of those solve it, post a comment back here and we can dive in to the more complex tests

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.

Try cleaning your RAM it should be the issue mostly 80%

You can check by rremoving the VGA cable if the system shows no signal mostly monitor should be fine

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