Just does not shrep the paper and smell like it is burning

If the motor will not run, then probably there's paper clogged in the shredder. Turn over the shredder, after unplugging the power cord, and remove the papers.

If the motor will run but not shredding any paper, then the drive gear has broken teeth. This is not usually worth fixing.
Hope this helps.

The most likely cause is that the shredded paper, has tightly wrapped itself in the blades. One possible cause is by shredding labels (like Avery Labels) or any paper which has adhesive on it. (Causes it to attach the cut pieces to between the cutters.) It reaches a point where there is so much bound up on the blades that even a single sheet of paper will cause an overload. The fix is simple to describe, but difficult to accomplish. You must go in and manually remove all of the paper bound up in the blades. It's not easy, I found that using a needle nose pliers worked best. Lot of digging and tugging (paper will pack between the blades very tightly). Sometimes a small, slotted screwdriver will aid in being able to pry out bits and pieces (it's not going to come out in anything but small chunks; at best). Don't forget to unplug your shredder before you start; those blades are sharp. This happened several times with my last shredder *Royal), but not once with my current shredder (Fellows). I tend to believe that the better quality shredders are worth the extra money. But any shredder will become a problem if you shred labels (like Avery) or paper products that has adhesive on it. (Another common mistake is shredding junk mail that has any kind of adhesive associated with it. Best to open and check first.) One other thing, ALL shredders need to be oiled on a regular basis. They make special oil for this, you can usually find small bottles of it at Wally World or the like. Best practice is to squirt some shredder oil in a serpentine pattern. over a piece of paper to be shredded and run it through. Do this whenever you empty the shredder bin. (Important for the life of your shredder.)

Try putting a piece of paper in enough to start it running, but not so far as to go into the shredder. See if it will run for a minute or two. Sounds as though it may be over heating.

Simple to solve!
Get some longnose pliers or strong tweezers.
Unplug the beast. You do not want to shred your finger nails, or your fingers.
Flip the mechanical part upside down. You will find small pieces of papers near the rollers. Pull them out with tweezers or pliers.
Keep hands out of harm\'s way, plug shredder and make it run in reverse for 1/10 of a second.
Unplug and remove more paper impacted in between rollers.
Repeat last two steps until no paper is seen by the rollers.
Plug and continue shredding your papers

Piece of advice. Do not shred your credit cards in shredder. Scissors are cheaper and do not mess your shredder!

It sounds like the shredder overloaded when you tried to shred the checkbook. If there is a smell of burned electronics this probably means that the shreader is dead. The plastic shims have nothing to do with the turning on and off of the shredder. Next time buy a shredder that is rated for at least 7-8 sheets, indicating a more powerful motor and sturdier blades. If the current shredder was repairable, it would be cost prohibitive over buying a replacement. Sorry for the bad news.

If you look at the blades, some are likely bent (probably the middle ones) causing the machine to not drop the clippings which makes it think that there's paper to be shredded. It's a common problem with this shredder and there's no fixing it because the company doesn't offer replacement parts. The shredder is an overpriced piece of junk. I bought mine at Walmart but our local store doesn't even carry them anymore because of all of the returns they've had.

yes, it's the plastic gear that's shredded in this shredder. the drive gear on the motor is metal, as are the gears attached to blades. between is a single plastic gear which is chewed up the instant resistance is great enough. fabulous engineering. not a difficult fix, but where does one find the replacement part?

Mine now just has the same problem. On mine it was because two of the cutting blades have become bent. It still shreds, but not as fast. You have to turn it on for a split second to see all the blades. You can only see about 1/4 of the blades at a time.
There is nothing you can do. And because my blades are bent it does't dispose of paper properly and also will not turn off automatically now.

Sounds to me like a the main control board is fried. That smell was probably a resistor or a rectifier burning. The fact that you hadn't oiled the shredder in 3 years didn't help, probably put an extreme load on the drive motor. You might be better off, shopping for a new shredder, unless this is a high end industrial strength model.

sounds like a malfunctioning input sensor