Today I cleaned up the spilt toner, or as much as I could manage of it, from the inside of my laser printer. This spill occurred during the house move (the manual probably contains some instructions on how to stow the printer for safe transport, which it didn't even occur to me to look for let alone read) and since then the rogue toner has been generating exciting yellowy-
So today I got round to the cleaning job: I pulled out as much of the innards of the printer as I could sensibly extract, wiped up some toner from underneath them, and now I've managed to put several sheets of paper through the thing and get them out again containing only the marks I actually asked for. This is good, and is one more item crossed off my list of things to do.
Unfortunately, it also means several of the fingertips of my right hand are going to be a bit yellow-