May I ask, I bought a samsung mono laser printer (ML2510) because like
everyone else, I was fed-up of my inkjet nozzles blocking. When the
toner ran out, I bought a refill from ebay. I think I was told you
could only use refills a couple of times and then you had to buy a new
whatsit, the big thing you pour the toner into. Is that true? Why is
that? Does something wear out?

I must have refilled it twice now but I must admit since the last time
I refilled it, the print has been grey rather than black. Have I done
something wrong? Or is it that my whatsit needs changing or have I
just bought cheap toner which isn't as black as the real stuff?

Thanks,
Stephen.