I had a quick search and couldn't find the lyrics. This is what I can remember of this song (and I'm not writing in all the lllllll's - it would take far too long!):

I used to play my wee banjo
And rest it on my knee
But now the strings have broken down
And it's no good to me

I took it the mender's shop
To see what he could do
And when he gave it back to me
It was as good as new

(Unfortunately!)