Screen unresponsive after replacement.

Hi, I have already repaired various iPhone screens, cameras, etc. But this time when finishing repair on an iPhone 5 16gb I realised that the Touch on the phone was unresponsive. I did my usual routine if any problems/malfunctions occur after repair, so I disconnected the battery to completely power-cycle the phone. After power-cycling it the issue with the unresponsive screen was gone. So I started to check on the phone if the front camera and the earspeaker were working. The camera was completely unresponsive and the speaker had a weird rattling noise when operating. So I opened the phone once more to replace those parts (luckily I had replacement parts sitting around). After replacement having the same issue with the unresponsive screen I power-cycled the phone again but it didnt seem to work this time. Home and Standby button both worked, so I rebooted the phone to see if that would change anything. Unfortunately nothing changed. Anyone have any ideas how to get rid of my problem?