Loose door handle

[skcheche1]

The handle has come loose and wonky on my back door. I have unscrewed and removed handle hoping to find that the cassette just needs replacing but it doesn't look like a normal cassette. Any ideas?

 

[Wayners]

I can see a silver screw in the centre. Try that

 

[crank39]

Generally uPVC style door handles are assembled by putting the lever part through the backplate and it then being peened over in a press, as handles are used, pushed and pulled they loosen up, sometimes the nylon washer falls out between the lever and backplate rendering them......we'll just broken and not designed to be repaired, that said that screw is intriguing and even I haven't seen one of them before