Wherever possible I like to fix things myself around the house and today I tackled a roller blind (persiana) that was coming apart. This isn't the first time either because the design of these blinds allows them to come out of alignment, so that when you let them roll down, one side catches on the channel and the whole thing gets caught up at an angle.
Obviously the slats are interlocking, but you can take them out individually, which is what I had to do because one was beyond repair. The only way to completely fix these buggers is to take them out and line them up.
Another thing to remember is to have a stop at the bottom so that when you roll it up it doesn't disappear into the roller. I just screw a block of wood at the bottom of the blind to prevent it going beyond reach.
There was a medium amount of cursing during this job, as you can imagine.