[Q] HTC one M7 Screen dead topic

Hi there can anyone help me please on this matter.

My wife has a HTC One M7. last week the phone fell in to the bath. I managed to open the phone up and clean it.
The phone was taken apart and cleaned correctly using the correct circuit board cleaning solution (sorry cant remember the name).

I then ordered a new battery as the old one was not holding full charge. I also ordered a new screen + digitizer as the old one was cracked.

I have put everything together and charged the phone.

The phone charges correcrtly and has no problems at all.

When i switch on the phone it starts as normal and makes normal sounds etc BUT the screen is dead.

There is NO life in the screen at all even though its a new screen etc.

I know that the old screen is working and even using that i still get nothing.

Has anyone else come across this issue ?

Are there any guides to test the screen driver IC etc ....???

Thanks for your help in advance