Question Dell inspiron 1564 black screen

Apr 7, 2020
I have a Dell Inspiron 1564 whose screen suddenly doesn't work anymore. It boots up, but the screen remains black. If I connect it through hdmi cable to an external screen, it doesn't show anything neither. It only works with vga cable, but it shows some blue vertical lines along the sceen. I did a diagnostic test and it came the message "error code 0321" and "lcd eDID - unable to access". If I let it boot up to windows desktop (through the connected vga external screen), after the sign of windows 7, it gives me a blue screen with the messages STOP: 0x00000116 and atikmpag.sys. The only way to get to windows was to go through safe mode, uninstalling graphics driver and then it boots up normally with the vga screen. The vertical lines along the screen remain. I tried to update the graphic driver through Dell and through AMD website, but the blue screen reappears. I also found out that with a resolution of 800x600 these blue stripes disappear for some reason...
What I tried to do until now was to change the lcd cable and the lcd screen, but none of them helped. After that, I read somewhere that if you press the power button and the letter D, the lcd screen shows some colours. I tried it, and every combination (old cable with old screen, new cable with new screen, old cable with new screen and new cable with old screen) worked, showing me the colours without problem at any pixel of the screens. But only that. When it is starting booting up, the screen remains black again. So, can anyone help me with this? What's going wrong?