Solved! Problem with Lenovo laptop

Feb 14, 2020
Lenovo ThinkPad E555
Model: 20DH
CPU: AMD A8-7100
RAM: 1x4 GB DDR3
OS: There is no hard drive in the laptop

The laptop turns on as usual with all the lights(battery light and start up light). But the screen is blank, I can tell the screen is working since I can see the backlights turning on.
The problem is that it doesn't output the starting screen and doesn't show the BIOS or any picture.

Things that happen while the screen in blank:
The laptop responds to Ctrl-Shift-Esc, Ctrl-Alt-Delete and also responds to just pressing the Esc button.
When I turn the laptop on, firstly the screen backlights turn on, after a second or two, the screen backlights turn off and turn back on.
After that the screen (backlights) just stay on, until the power off button is pressed.

Methods that I have tried already:
I have tried connecting it to a different monitor, but I don't get a picture there either.
I have tried the hard reboot methods, but didn't get any results.
I tried reseating the memory.

The only other thing that I notice is, that the bottom of the laptop near the heatsink is getting a little hot.
The AC adapter looks fine.
The laptop isn't beeping any beep-codes or flickering any lights either. The lights that do turn on when pressing the power button stay on as normal.

I just want to know if the problem is the graphic chip or something else.
From GregTheSlav

Thanks dude, the Linux USB boot actually fixed it somehow. The main screen still doesn't show the picture, but when I plugged in the external one and pressed a few buttons, it finally did display a picture. So what would you say the reason for the main screen to not show the picture, but the external one does would be?

Once again, thanks for the fix/solution. "
Might be a bad connection between the motherboard and the display
ribbon cable defective

or the screen itself is faulty

I would replace the cable first (only about $10) and if this doesn´t work, replace the screen or live with an external monitor

an unusual fault would be a motherboard issue