Laptop screen is not displaying.

I put my laptop to sleep mode, while the USB flash drive is plugged in.

I pressed the power button to resume my laptop from sleep, the little blue lights on the machine indicated that it did wake up, but the screen was not displaying.

I pressed the power button again to turn it off.

And then turned it on again, the screen shown the BIOS screen as the following;

DELL
Inspiron 1525 series
BIOS Revision A16

After that, the screen turned black, didn't show anything.

But I can hear the Windows sound (Windows log in sound).

I unplugged the power cord, took the battery out, and held the power button for 60 seconds,
then put the battery back in, plugged the power cord in, and turned on the laptop,
the screen was still not working.

I repeated these steps, still got the same issues.

Finally, I shined the flashlight on the screen, I was able to see all the processes since the machine started working, the BIOS screen, Windows logo, log on screen, and finally my desktop, but all these were very dark, without the flashlight I couldn't see these.

My laptop is Dell
Intel® Pentium® Dual CPU T2390 @ 1.86GHz 1.87 GHz
Windows 10

How to fix this problem?

I don't have an external monitor to test this laptop screen.