HP LaserJet 1100 All-in-One Printer series - Manual (Page 91)

EN Cleaning the printer 81
Cleaning the printer paper path
This process uses copier-grade paper to remove dust and toner from
the paper path. Do not use bond or rough paper. Use this process if
you are experiencing toner specks or dots on printouts. This process
will produce a page with toner debris, which should be discarded.
1 Ensure the printer is loaded with paper.
2 Ensure the printer is in the Ready state.
3 Press and hold the GO button for 20 seconds (if released before
20 seconds the printer will perform a reset). Paper will feed
through the printer.
Note After holding the GO button for 20 seconds, each of the three printer
lights will blink until the cleaning process is complete.