Display shows only backlight but no screen after replacement

Hi,

my phone dropped and the glas broke so also the touch didnt work anymore properly. I bought an replacement screen on aliexpress.com and built it in and the screen shows only at the beginning green lines and then a blank screen, only backlight. After a few seconds the red light starts to blink 3 times and the phone restarts with the same procedure.

I tried to switch then my broke screen to test it but while i have dissassembled it there are a lot of glass pieces got away from it so i think the original screen also dont work. But what could it be that the new screen does not work? Because the seller guarantees me that its tested and worked before it was shipped.

Anyone had the same problem after the screen replacement?

Thanks, stanley