Hello, this is Ava with Think Crucial.
If the dust cup is too full, there is no space for the dirt to go when you are vacuuming. To fix this, remove the dust cup and empty the it.
If your vacuum is still not picking up dirt after emptying the dust cup, there may be something blocking the airway. There are two places where you can check for a blockage: the dust cup air duct and the intake opening behind the brush roll. To check for a blockage in the dust cup air duct stand the vacuum upright and remove the dust cup. Now you can disconnect the super stretch hose and check for clogs in the air duct behind the dust cup. If that is not the case, to check for a clog near the roller brush lay the vacuum down. Next check the opening behind the brush roll for clogs. If there is debris, clean the opening with scissors, carefully cutting away any debris.
Uncleaned filters may also the reason why your vacuum has lost suction. To clean the foam and felt filters, remove the dust cup and pull out the two filters that are on the top of the motor base. Rinse the filters with lukewarm water until the water is running clear. Let the filters dry fully before putting them back into the vacuum.
If your vacuum is still not picking up dirt, you may need to replace it.
Unfortunately, if none of the other solutions worked, your motor is going bad. Most of the time a new motor costs as much as the vacuum itself and it is not easy to replace the motor. It may be time for a new vacuum.
You can purchase a wide variety of high quality Shark replacement parts for your Shark vacuum direct from Think Crucial with free shipping and an exclusive 10% coupon for Fixya.com readers, use code: FIXYA10
I hope this was helpful.
Think Crucial Customer Care