PLZ HELP!!! iPod touch 1G keeps on rebooting(please read first )

[konvikted]

hello guys

this is my first post, and i have looked a lot around this site for similar problem but couldn't find any..

i need your help so badly..

you see i have this ipod touch of a friend, he gave me to repair
now the problem is:-


the ipod touch will never ever shut down!!!!

this problem is really weird, it wont shut down at all
i hold the two buttons to gather , the screen goes off & after 1 second it lights up again with the apple logo and then goes off after 5-6 secs and reboots again with the apple logo AND CONTINUES FOR EVER AND EVER

THE IPOD TOUCH IS NOT AT ALL JAILBROKEN


now if the USB is connected while its rebooting, it boots into the springboard and shows that slide to power off thing on top every time it loads into the spring board, and when its in the springboard
everything works fine but the sleep button wont work??

WHY..???

now here are the things i tried..
1) i restored it successfully
2) i even upgraded the software to latest firmware successfully
3) i tired to jailbreak , but it never enters DFU Mode for some reason

What could possibly be the problem here,please help guys