A roller blind that has stopped rolling is usually one of three things, and two of them you can check without tools.
Start with the simplest thing
Look at the chain. If it is hanging loose or has come off the sprocket at the top, the blind is not broken at all: the chain has jumped. Feeding it back onto the wheel usually sorts it, and it costs nothing.
Then check that nothing is binding. A blind that will not come down is sometimes just rubbing on a window handle, a curtain, or a piece of furniture that moved. Pull the blind down by hand, gently, and see whether it catches.
When it is the spring or the clutch
Older roller blinds have a spring, and springs lose tension over years. The symptom is a blind that creeps down on its own or needs a hard yank every time. That is a repair, not a replacement: the fabric and the tube are usually fine.
Newer blinds have a clutch instead, and a clutch fails differently. It spins freely and the blind will not hold position, or it is stiff enough that the chain jumps. Both are a parts job, and cheap next to a new blind.
What not to do
Do not cut the chain shorter to try to fix a tension problem. Chains are a fixed length for a reason, and a short chain on a tall window is a genuine hazard, especially where children are around.
Do not force a jammed blind down. The bracket is screwed into a reveal, and the thing that gives way is usually the plaster, not the blind.
Questions about this
Can you restring a blind instead of replacing it?
Yes. Restringing and re-tensioning are usual repairs; the fabric is rarely the part that fails.
Do you repair blinds you did not supply?
Usually, yes. We will tell you honestly if a repair is not worth doing.
How long does a roller blind last?
The mechanism typically outlasts the fabric in a sunny room, which is why fabric replacement is common.
Free measure and quote
In-home, no obligation, and we will tell you what your windows can actually achieve.