The most common reason for slats getting stuck and unable to be lowered or raised is that their cord is trapped in its lock mechanism. To release it, raise the cord until it's level with the headrail at the top of your blinds, and then gently tug on it. This should release the lock mechanism and set the cord-free.
If you experience trouble rolling the blind upwards, the problem could be a loose or uncoiled spring. If this is the case, fixing it is simple. All you need is to get a pair of pliers.
Test the Friction Clips
Therefore, if your friction clips aren't operating as they should, it could be the reason why your cordless blinds won't go down. Sometimes you'll need to remove a couple of these clips in order to get the blinds moving again.
Readjust the tension
The issue you are having could be down to a lack of appropriate tension. To fix this, remove one end of your cordless roller blind from its bracket. Spin the blind one way while ensuring the spring stays within the bracket. You will increase the tension and get it back to a suitable state.
First, make sure to fully tilt the vanes to the open position before trying to draw them across the window. When it's hard to open the blinds, it may indicate that the cord is frayed or wearing. Follow the entire path of string and inspect it for wear. If necessary, replace the cord.
Lift Cord or Pull Cord(pictured first)
The mechanism that raises and lowers your blind or shade.
One may wonder what happens if there isn't any power or if the batteries in the remote controls run out. Will you be able to operate the blinds? Some motorized blinds can be pulled up and down manually in case there is a power problem. But some stay as they are until you fix the remote control or restore electricity.
To adjust the height on these shades, pull the bottom edge of the shade down and slightly toward you to release the lock. Then, adjust the shade to the desired height by letting it rise or pulling it down. To lock it into position, push the shade slightly away from you, toward the window.
Cellular shades, also known as honeycomb or accordion shades, are fairly easy to repair. The most common repairs include restringing the shades, replacing broken mounting brackets, and replacing cord locks.