The brush wont rotate!!!! how can i fix that??? It stated smoking! I opened it and found the band broken. I replaced it and the brush will not rotate! why

I am hoping this is a vacuum cleaner if which you speak.
If so, one of 2 things is likely the cause.
1) The belt has either slipped off or is broken, and the brush area must be opened and the belt dealt with.
2) On most machines, the brush rotates and has two "bearings", one on each end.
If one or both become clogged with hair or dirt or whatever, the bush can "bind up" and will no longer rotate until this is cleaned.
God bless your efforts.

Without knowing the brand and model number, I can't assist too much. However, most all of them have a belt that turns the rotating brushes or "beater bar".

It looks like a large black rubber band, and does wear out at times causing this condition. It would be located under a removable panel on the bottom of the unit.

you need to replace the drive belt look for screws on bottom and access plate left or right.

Typically when the brush does not rotate and the motor is running the belt has broken and needs to be replaced.

Is this the Lightning model? How old is it? You may have to just replace the belt.

Also, the front brush motor will not engage until the power is turned on and the handle is in the down position. In the upright position the brush motor wont engage. Typical faults will be the belt is broken and needs replacing or the fornt brush motor needs replacing.

Needs a new drive belt. Find the screws holding the bottom panel onto the floor section of the vac. take out those screws and you should see the motor and the brushes and a broken belt underneath the panel. Check that the brushes spin freely. If not you may have something like hair or string or something jamming the brush. If so cut out the obstruction and then rotate the brushes again and look to see if they rotate evenly, without wobbling because in some vacs if the brushes become jammed and run like that for a while sometimes it wears out the bearings or bushings holding the brush in place and if they are worn you need to replace those as well or when you replace the belt and run the vac it wont take long to break the belt again.

Sounds like the rubber drive band has not been replaced properly to drive the brush and/or the brush was not properly cleaned. You can find the manual here:
http://dl.owneriq.net/4/4d79dca8-65d8-4c46-a58a-a2fef1f89635.pdf

The belts are probably broken, stretched or worn. I would try replacing the belts if you haven't in a while. You can get the belts you need here:

Bissell 1699 Replacement Belts

If you are handy with a screwdriver undo the casing to access the roller. Once open usually about 4-5 screws you will see that the drivebelt ( rubber band ) has broken. This is the piece you need to replace. Usually most electrical store selling cleaners have these. Take the piece along or get the part number from the manual and replace it yourself. Cheaper than having a tech do it at $90 an hr plus the $5 part

I had the same problem. I found that the brush actually melted to the end cap (the one with the square/ovalish end). I was able to pull it off with some force and applied some WD-40, but that only worked for one more use. The brush has again melted to the end cap and it is too deformed to try and fix. I suppose I will have to search for a new brush, but this model obviously has some innate flaws.