Motor on / Blades don't move.

Most likely one of the gears popped off or cracked. The blades are gear driven by a motor and it's pretty straight forward. If the blades aren't moving, then it's probably a gear problem since you said the motor runs.
Not much you can do without taking it apart.
Good luck. =)

It is possible that a small shred of paper is lodged at the sensor underneath the cutting blade.

1. • 1 Unplug the paper shredder. Empty the shreds from the collection bin. Pull as much stuck material as possible from the top and bottom of the shredder blades with pliers or use canned air and blow the edges of the blades.
     
   • 2 Place the paper shredder back on the collection bin base and plug the shredder back in. Rock the shredding direction back and forth between forward and reverse.
     
   • 3 Make two passes across the cutting blades while drizzling synthetic shredder oil. Switch the direction to forward to run continuously for one minute.
     
   • 4 Lower two sheets of clean paper into the shredder. The paper removes excess oil, metal fragments and debris from the cutting blades. Blast the blades with compressed air when you notice a build-up of small paper scraps that may cause a jam.
     

Hi,

Ensure the wastebasket is empty then move power switch to the REVERSE position. This will reverse the jammed paper out of the shredder. If shredder jams again, alternate control switch slowly between REVERSE and AUTO (l) positions to attempt to move jammed paper completely through the shredder. If the shredder jams in reverse mode, move the switch to AUTO (l), depress the manual forward button located on the center of the shredder head and allow to run for five seconds. If jam does not clear, move switch to REVERSE again and allow to run for five seconds.

Repeat this process until jam is cleared. If necessary, turn off shredder and use care to grasp the paper and carefully pull out to clear jam. Once cleared, move switch to AUTO (l) to continue shredding. The jamming may be happening because the cutting cylinder needs to be oiled.

Follow instructions to oil your shredder;

To keep your shredder in top condition, the cutting blades need to be oiled every so often (for frequency, please refer to your owner's manual). We recommend using Powershred® Lubricant or a vegetable-based oil (such as corn or canola) in a non-aerosol container with an extension nozzle.

Caution: Never use flammable synthetic oil, petroleum-based, or aerosol lubricants to oil the cutting blades. Some agents may combust, causing serious injury. NEVER USE WD40.

1. Depress and hold the reverse button down.
2. Put the tip of the oil bottle in the paper entry and make one or two sweeps the length of the entry while squeezing the oil bottle.
3. Move the power switch to Auto (I) position, or depress the manual forward button (depending on model of shredder) and allow the blades to run at least three seconds.
4. Move the power switch to Reverse (R) position and allow it to run for at least three seconds.
5. Repeat steps three and four above at least three time.

Regards.

There is a screw hidden under one of the stick on labels. Remove that and the top comes just fine. I got it torn apart, completely cleaned of debris but the rollers still don't turn. I noticed an electrical arc when the switch is pressed so the unit is toast.

Inside the motor assembly there are a series of nylon cogs , a large one of which interacts with a metal one.  This is the most likely place you have one or two teeth missing from the large nylon cog that drives the shredder blades.

If the blades rotate then the paper should go in...just be sure the blades are turning in the forward direction and not in reverse.Also make sure you lubricate the blades with shredder oil.

Sometimes the main gear is attached to the motor with an ALLEN SET SCREW

Is the motor just humming after the 2 rotations? If you are over oiling the unit, tha shreds will soak up the oil and start sticking to the blades and begin growing a paper tumot in side the cutter shroud, whish in turn will start to slow down and jam the cutter asm and motor. Best to take apart and thoroughly clean.

I’m happy to help further over the phone at https://www.6ya.com/expert/jayw_0e86fb055a7b73de

Look for a wadd of paper jammed up in the blades, it don;t take much to plug them up you can over look this very easely. DFD

Sorry about that, there is no gears for that machnie. Have a great day!