Power failure and digitiser sensitivity

Okay, hopefully you can advise.

Getting a device in that's had a previous screen replacement and the second time around this was because the digitiser was causing phantom contact during calls. The last screen replacement I did I teste with no phantom touches but client is reporting it again.

Additionally the device had reportedly lost charge and is no longer booting past apple logo, with numerous lines (yet to see this myself) across the screen.

Any ideas? Possible solutions?

Thanks in advance

Will