After screen replacement the phone only charges until it boots up

Hi,

i changed the broken lcd screen from my iPhone 4 32GB. Everything worked after the repair as expected until I had to charge the device.

The device was discharged until it shut down by itself.

When I connected the power to the connector the screen shows the charging signal and after some minutes the device boots up and shows a charging of 4% but with no charging sign.

After booting up the phone starts to discharge and this process restarts.

First I thought it was the connector, so I replaced it, then I tried a different battery but this was also not the solution.

iTunes is also not responding or identifying the iPhone.

Does anyone have an idea how to fix my issue?

Thanks in advance!

Sincerely

DotKim