Compaq presario f577cl wont turn on

the WiFi isn't on if it's orange press that key and it will turn blue when it is on..with the battery take it out , count 20 seconds then put it back in and it should work

Connect the monitor to some other computer, e.g., a notebook, and see if it does the same thing. If it does, then the monitor is the problem.
If it does not, then your computer is not putting-out any "video" signal, and so the monitor goes to "sleep".

If you have MORE than one VGA-output port on your computer, connect your monitor to the "other" VGA port.

Or, press-and-hold the ON/OFF button on your computer, to force it to completely shutdown.

Have you tried turning it on and selecting the function key combination for the screen? For example some screens use FN+F7, hold down the Function key and F7 to cycle between presentation modes.

In case it is in warranty, so not try to repair it as it may void the warranty. It is better to take it to a service center. Moreover in this case, it seems to be fault with the screen, so your data would be safe.

I will need more information here but it seems that either the battery needs a charge or the power adapter has failed.
2. or the unit is in the sleep or hibernation mode.

Is the battery fully charged?

have u installed any ram other than the one that came with the laptop?if yes then remove the Ram and try once more

Well... Sleep and Standby are not the same. While Sleep only turns off a few things, like display, WiFi, and HDD to save energy. Standby saves your session to the Hard Disk, the reason why the laptop seems unresponsible. This is the reason to uncheck Stanby if you want a fast wake-up.

When you plugged the power cord back in did the green light on the power cord battery light up. How long have you had the cord. Make sure the power cord is working properly.

just do one thing go to your nearest compaq service centre and tell them your problem then they will do it right