Error code 6A90 or "APP sensor error" occured during paper feeding or purging. Solution 1: check for foreign material or paper debris around the purge drive system unit; - remove foreign material. Solution 2: check for foreign material or paper debris around the ASF unit; - remove foreign material. Solution 3 : If other solution fail, replace one off the following part - Purge drive system unit - Logic board
Reset printers and cartridge. Printers problem solving,tips, tricks and tutorial.