Blank screen when turn of, just fan on

What do your LEDs do when you turn it on?

If you have no flashing of the drive activity LED, then the system is dead.

First suspect is your HDD or SSD. Second is a MB failure.

If the drive LED is flashing for the time it used to take for the system to boot up, then your system is likely functional except for the display.

Do the flashlight test on the display to see if it is a backlight problem. If there is no video, then it is either a display, a cable or the display driver.

If you can connect to an external display (or TV) that will verify the rest of the computer. You can then check in the device manager for your Display adapters and monitors. It might be bad display drivers, so you can try reinstalling them.