Iphone 4 screen unresponsive after replacing screen?

After cracking my screen I ordered a replacement off of ebay,… Now it doesn't respond to touch… Everything else works… All cables are connected properly and I did a restore on iTunes and it still won't work… Help.

It could possibly have been a faulty part, which is annoying:/ message the seller on eBay and explain your situation, see what they tell you to do and if nothing works then I'd ask for a refund or a replacement screen.