If the cords still don t pull or adjust the height of your blinds then you may need to force the lock mechanism open.
Fix venetian blinds string.
If bottom rail is metal remove end caps and clamps from rail to expose knotted cords.
If your blind has this you can easily move that slat up to replace the broken or damaged slat.
Untie knot on side opposite lift cord and butt end of new cord to this end.
Remove the slat and insert the new one.
You can do this with your hands and fingers.
Lift the bottom of your blinds even if they are already stuck at the top near the headrail.
Pull the cord toward you and cut the knot off the end of the cord.
Look for the end of the cord where it is tied in a knot.
They are fairly easy to repair.
Ends of cord are secured to underside of bottom rail.
If bottom rail is wood knotted ends of cord are simply stapled under ends of tapes.
Remove the cap covering the hole in the bottom rail of the venetian blinds.
Remove the bottom rail buttons and untie the lifting strings.
With blinds down tilt slats horizontally.
The blinds normally use two lift strings to function and if even one of them gets broken you will end up with non functional and dis oriented blinds that certainly don.
The most common repairs include replacing broken tilt mechanisms replacing broken strings and replacing broken valance clips.
How to fix broken blinds strings if the strings of the blinds get broken you may end up with blinds that either don t go up or don t go down and make for a disheveled look.