This can be because you need to adjust the tension or probably the pulley is no longer aligned. So find out if the shaft is no longer straight also if the belt requires tension.
Locate the filter compartment on the vacuum. It is usually located under the dirt cup or canister.
Remove the filter compartment cover by pressing the latch or pressing the button and pulling the cover off.
Take the old filter out of the compartment and discard it.
Place the new filter into the compartment, making sure it is properly seated.
Replace the filter compartment cover by aligning it with the vacuum and pressing it into place.
Make sure to properly maintain and replace the filter as recommended in the owner's manual to ensure optimal performance of your Eureka 4335 DX vacuum.
Nothing you have described should cause it to fail. Claim on the one year warranty irrespective of how long you have had it. What happens if you remove the hoses and turn the machine on? Does it suck from the hole in the body where the hose attaches? If it doesn't then the disc that is attached to the motor has sheared off the motor spindle. Was the stone in the bag, or did it punch a hole in the bag and meet the motor?
https://www.google.com/search?q=Eureka+Mighty+Mite+3670+warranty
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If you have the time allied electronics has extensive electronic parts or if you have a local electronics shop. Many years had an old Eureka Canister switch failed and I found a toggle switch that fit perfectly . It lasted another 7 years.
I am not sure about your "Boss", but a lot of vacuums have thermal cut-off switches built into the circuit so if the machine overheats from things like clogged filters/hoses the switch kicks in and kills power. You usually can NOT reset it manually ... you just have to wait until the machine cools down.