After replacing digitizer, the tablet wont power on

Hi people, I am after some advice on what could potentially cause that an ipad 6th gen is not powering on after replacing the digitizer.

I have had a few times where pressing the power button do nothing, but then connecting it to a power source wakes it up.

If i plug into a iPad charger, nothing happens.

If i plug into a computer with iTunes, nothing happens.

It is as though the battery is not connected and not giving power.

I have not messed about with the battery and it did work after i connected the digitizer the first time and a few times after that. all of the sudden the ipad just seems to not work.

any potential suggestions for a solution?