The following characteristics of the PSVita crashes and error (Can not be switched from the status IDLE / Sleep state, although the battery remaining half over):
Playstation logo visible on solid blue.
When pressing the POWER ON, PSVITA not be lit and even no response at all even though the button is pressed on repeatedly or held for several seconds.
Usually if a problem has occurred error / hang like this, of course, hard-reset action is necessary to re-ignite and re-boot the system PSvita.
But the challenge to disassemble PSVITA by removing the battery to do a hardreset is a bad idea, because you can do hard-reset PSVita without having to dismantle and remove the battery of this handheld console.
Here are the steps to do hard-reset on PSVITA:
1. First plug the USB power charger on PSVita
2. Once the USB power charger plugged in, the color of the previous playstation logo in blue color changed to purple. Then wait for 10 seconds before continuing the next step towards improving.
3. Hold down the Power ON button + L + R buttons simultaneously for 20 ~ 30 seconds.
4. After holding down the Power ON button + L + R Buttons for 20 ~ 30 seconds, the playstation logo was changed to the color purple orange yellow. This marks his PSVITA has been successfully hard-reset.
5. Press the Power ON button again and will return to BOOT PSVita Operating System.
6.Finally PSVita can return to work with ready times.
Source : http://jagatplay.com