For failure isolation, energize the suspect PC board. Spray on board to determine the area where the failure is occurring. Attach extension tube and spray on individual components until the failed component has been isolated.
The can of duster must be held in an upright position when spraying. Do not tilt can more than 40 degrees during spraying operation or shake during use. Before use, press actuator to clear valve of any liquid product. Extension tube can be used to remove dust in tight areas. Use short bursts to prevent cooling of can.
If the can and valving is intact and undamaged, it will not leak or spoil, so can sit on a shelf for as long as 10 years.