Kitchen roller blind

'Went to let up the kitchen blind this mornig & the whole thing fell down!I've noticed that there seems to be a little white plastic piece missing off one end.....would this be the cause of it falling?If so,can that be replaced?It's a bit of a nuisance,having it like that.....

The pin must have sheared off at the end, I reckon these pins should really be metal and not plastic to resist this. You may be able to get a replacement cap from a blind shop, alternatively it may be possible to repair the existing cap by drilling a small hole and gluing a metal in place (use an expoxy type glue); but how long will this fix last?