Look at the head rail or long metal piece that holds the blinds to see if the cords are stuck in them. This could be the problem if the blinds will not hang evenly. Pull the cords out and lift and lower the blinds with the drawstring.
Lift the blinds out of the brackets and untie the knot in the cord just below the bottom rail. Set the blinds on a flat work surface and remove the cord from the slats in the holes to replace frayed or broken string.
Set the old string beside the new one to measure the length. Snip the new one according to the length, then insert it through the opening in the cord lock in the head rail. Thread the strings through the route holes in the slats.
Feed the string through the hole in the bottom rail and tie a knot in the end. Set the blinds on the wall and make sure they hang correctly.
Unhook the blinds from the mounting brackets to fix broken slats. Set the blinds on a flat surface. Take off the bottom rail and untie the knots, then slide out all the slats up to the damaged one. Insert a new slat in the string ladders, then replace all the slats. Push the bottom rail back into place. Tie the cord in the end to secure it. Set the blinds back into the mounting brackets.