Paper had jammed, open printer and a lot of toner was spilled from the spout of drum because door to toner cartridge was not open. Removed toner cartridge, cleaned mess. Reinserted toner cartridge. Removed jammed paper from right side. Closed doors and that was when the grinding began. Replaced drum with new drum. CH is displayed in the Counter window. Don't know what to do. Bought printer used and it didn't come with a manual.