Power issue after replacing screen

[klanders]

I replaced my T410 screen and got some issues which now focus on one critical problem. When I shut down the system, the screen will turned to black (as I assume), but the backlight is still on so that the screen looks like bright grey. And if I pull the power line off, the screen shuts down, even with the battery. So it looks like the power line keeps powering the backlight no matter if the OS is working. Any suggestions?

[jayton4]

What about the fan? Can you hear it or feel any air after shutdown when the screen is still black?