new touch screen stops responding in intervals after replacement

I just replaced a cracked display (which was still responsive) with a new one (display and mid-frame combo).

Everything works so far, but the touch-display itself stops responding every about 10 seconds for about 3-4 seconds at a time. Did you ever experience something like that? Have I done something wrong or could the new panel be faulty?

A response would be highly appreciated.

EDIT: The problem is a little reduced (though not gone completely) as long as the phone is connected to the loading cable. It responds for longer periods of time and the time of it being non-responsive is shorter.

I'm expecting a new battery in the mail tomorrow, when I put in it I'll double check all connections, but it would be great to know what to look for....