Laptop screen stays blank after lid is reopened

There is a post from devilkin that solved my problem, here is the solution:

It requires the ACPI VIDEO module loaded.

Create the file /etc/acpi/lidswitch.sh with these lines (don't forget to chmod +x on it):

#!/bin/sh
# /etc/acpi/lidswitch.sh
# Re-activates the screen when the lid is opened again

LID_STATE="/proc/acpi/button/lid/LID/state"
LCD_STATE="/proc/acpi/video/VID1/LCD/state"

grep -q open $LID_STATE

if [ $? -eq 0 ]; then
    echo 0x80000001 > $LCD_STATE
fi

Then put these lines in /etc/acpi/events/lidswitch (lidswitch not being a folder, but a file without a file extension):

# /etc/acpi/events/lidswitch
# This is called when the lid is closed or opened and calls
# /etc/acpi/lidswitch.sh for further processing.

event=button[ /]lid
action=/etc/acpi/lidswitch.sh

Extra help:

(1) Use gedit to create these files. So open up Terminal, then type in 'sudo gedit' (without quotes) and copy and paste the lines above.

(2) Use nautilus to apply the "chmod +x" property to the file. To do this, open up Terminal, then type in 'sudo nautilus' (without quotes) and the navigate to etc, acpi, then right-click on lidswitch.sh, navigate to Properties, then Permissions, then Allow executing file as program, then click Close.

Create the file /etc/acpi/lidswitch.sh with content (don't forget to chmod +x on it):

#!/bin/sh
# /etc/acpi/lidswitch.sh
# Re-activates the screen when the lid is opened again

LID_STATE="/proc/acpi/button/lid/LID/state"
LCD_STATE="/proc/acpi/video/VID1/LCD/state"

grep -q open $LID_STATE

if [ $? -eq 0 ]; then
    echo 0x80000001 > $LCD_STATE
fi

Place a new script inside this folder?--->>/etc/acpi/events/lidswitch

Then put this in /etc/acpi/events/lidswitch:

# /etc/acpi/events/lidswitch
# This is called when the lid is closed or opened and calls
# /etc/acpi/lidswitch.sh for further processing.

event=button[ /]lid
action=/etc/acpi/lidswitch.sh