White iphone 4s, on vodafone , 4 weeks old , faulty ?

White iPhone 4S 16gb. Comes boxed with everything cases x2, charger , instructions, earhones etc I smashed the screen had no insurance so decided to fit a new screen myself. Ive done a wonderful job however the phone sometimes doesnt power on all the time, when it does it works just as normal! full network coverage, wifi, etc , The new screen that was fitted is also a black screen. so you may want to change the screen to suit you. No scratches. I will provide a receipt upon collection. I WILL NOT POST, OR USE BANK TRANSFERS, PAYPAL ETC IT IS EITHER CASH ON COLLECTION FROM BB4 AREA OR I MAY BE ABLE TO DELIVER. PLEASE DO NOT WASTE MY TIME AND ALL SPAM EMAIL WILL BE REPORTED . THANKYOU