Why is my touch working for like 10 seconds?

I have an iPod Touch 5th Gen which was working fine until I was playing a game and the touch on it suddenly stopped working. I tried my best but couldn't revive it again. I connected it to iTunes and factory reset the iPod assuming it might be a software bug. It still doesn't work BUT, I restored and it came to the 'Hello' page. The touch suddenly works. It works for 5-10 seconds or so and stops again. I did everything and entered the wifi password too. I signed in but I put my password wrong and now it doesn't give me enough time to enter the password again! Please be so kind as to help me.