screen not responding after replacement with low memory - HELP!

I replaced digitizer and LCD assembly on a Galaxy S4. It seemed to work fine initially, but client brought it back saying it stopped responding. The areas where the LCD shows does not respond (even though when I just turned it on it started responding for about a minute then completely stopped), but the touch buttons on either side of the home button respond. I going to try to reopen the phone and unplug/replug the digitizer from the logic board to see if that helps but I have a couple of concerns. I noticed that the phone says that memory is low and that some system features may not work as well as another notice stating that storage space is low as well. Could low memory and/or low storage space cause the digitizer to stop responding to touch?

Anyone ever seen this happen before? Any ideas on how to resolve this, other than the obvious "get another new screen"? Thanks in advance for any advice given.