how should I do so my ipad could be detected on iTunes?

My ipad is still no life. the screen is off. and i have pressed the power key and the home button at the same time but still off. i charged my ipad and no indicator of the battery on ipad screen.

now, i need to restore my ipad. the ipad's already connected to the laptop by usb. but the laptop couldn't find my ipad absolutely with the iTunes too. Help pls. thanks.