Filter not clicking or emitting clean air smell and dust is flowing like filter is not energized

I think my air flow sensor might be the problem. This unit is only a couple years old and in excellent shape. No broken thin wires or anything. I cleaned all the contacts also. But the top panel is butted up to the heater. I would have to take it completely out to check the sensor. It might come down to that.

MAKE SURE THAT YOUR CELL(S) ARE CLEAN ... CLOSELY INSPECT TO SEE THAT THERE ARE NO BROKEN IONIZING WIRES (THE SMAAL STAINLESS-STEEL WIRES THAT ARE BETWEEN THE COLLECTOR PLATES). MAKE SURE POWER GOING INTO UNIT TO IS "OFF"!!! ... NOT JUST THE SWITCH ON THE UNIT. THEN TRY THE FOLLOWING: THIS AIR-CLEANER THAS A AIR-FLOW SENSOR THAT SOMETIMES GETS CLOGGED ... IT IS INSIDE THE TOP CONTROL PANEL. THERE SHOULD BE A DIAGRAM UNDER THE CONTROL BOX COVER PLATE TO ASSIST YOU LOCATING THAT SENSOR. MAKE SURE IT IS CLEAN. THE HIGH-VOLTAGE TRANSFORMER BEING BAD USEUALLY WILL SMELL LIKE BURNT WIRING. AND WILL LOOK BURNT. MAKE SURE YOU SEE NO LOSE WIRES ... SOME TIMES THE SPARK-PLUG LOOKING WIRE GOING TO THE CELL(S) CAN BURN OFF ITS CONNECTOR. YOU CAN CHECK THE DOOR SAFETY SWITCH TO MAKE SURE IT IS MAKING CONTACT WHEN HANDLE IS PROPERLY CLOSED. GOOD LUCK ... HOPE YOU HERE THAT ZAPPING SOON ... BY THE WAY ... IF YOU GET A POWER LIT ON ... GIVE THE RETURN-AIR DUCT A SLIGHT BANG ... IF IT IS WORHING IT SHOULD SNAP CRACKLE AND POP FOR A FEW SECONDS. MAKE SURE YOU SEE NOTHING (HAIR?) LYING ACROSS THE PLATES OR IOMIZING WIRES ON EACH CELL IF YOURS HAS TWO. ELECTRIC AIR CLEANERS ARE ONLY GOOD WHEN THEY ARE KEPT CLEAN ... PET HAIR IS A CONSTANT MAITENCE PROBLEM AND CELLS SHOULD BE LEANED EVERY TWO WEEKS. FOR BEST PERFOMANCE. Joe_Rex 40+ years Hvac Contractor (retired)