fabian_meier6 years ago+110Works fine last time. However, this time it worked for a few weeks, but then once the message "Invalid Toner" came up and I could no longer print. SOLUTION: I taped over the 4 metal contacts at the back of the toner, and it works! (Just with the message "Toner low"). EXPLANATION: the built-in chip is simply ignored as it is no longer accessible, and the toner works even without a chip (until now...).Show in original language (German)1 answerBrimstone6 years ago+121 Helpful answerThanks for the tip!Show in original language (German)