Ksb50b3 doesn't turn on hums

sounds like its your motor.

Can you check it without the beaker on? It could be the blade seizing up, how free does it turn by hand?

http://www.appliancepartspros.com/search.aspx?model=ksb50b3

Colin if another K/A model jar would fit K/A would know and should have told you.

the GFI is the receptacle in your kitchen, not on the unit itself,, the reset is the small red button in the middle of the receptacle ( sometimes gray) you just push that in to reset it,, newer homes have these in restrooms and kitchens for safety issues , however, back to your problem, try plugging the unit in to a receptacle without a GFI ,, if it works, its due to the high amps needed to start your blender and it trips the circuit. if it doesn't work,, Just take it back where you bought it , so you don't void any warranty on the unit and just get another one

Well it might just be over heated, let it cool for approx 20 minutes then restart if it doesn't then u may try switching electrical outlets, if that doesn't work then it needs to be replaced. I hope that this helps, if not please let me know and i will try and help you out as much as i can.

Available replacement parts can be found here:

http://www.directpartsandproducts.com/blenders-bl9000-c-1_4_60.html

or here:

http://www.abtecparts.com/Black_&_Decker_blenders_BL5000BL6000.htm

I have not seen the drive gear made available. You could try making an inquiry with either of the above sites to see if they can locate a replacement. Alternatively contact a local small appliance repair shop; they may be able to scavenge the part from another blender.

If it is brand new I would take it back.

I have not seen this problem with ours yet but if turning up the speed doesn't help (first thought would be the motor's overloading because you're using hard foods in it on a low setting). If it shuts off even under light loads, judging by the manual it's something you need to send it in for. See if there's a service center in the area. These Kitchen Centers aren't made any more and it's unlikely you can fix it yourself.

If you have a Kitchenaid Blender (model KSB50B3 or similar) and the rubber teeth on the coupling (that spikey rubber thing on top of the base) broke off (see picture), here is how you can fix it yourself! The Task: The coupling is screwed onto a vertical shaft like a button mushroom. The shaft is round with two flat sides. You need to find an U-shaped thing [such as a wrench] to secure the shaft and loosen the coupling by turning it CLOCKWISE. What you need: 1. New coupling: Part number KA-9704230. Shouldn't be more than $6. I got mine at www.goodmans.net. Their shipping fee is very decent and the service is also good. 2. An U-shaped object: Some had success with household forks. That didn't work for me. Most successes came from the use of ignition wrenches. There's only about 1/4 of an inch between the coupling and the base, and these very thin wrenches can get in there. You will need size 5/16 or 9/32. I got mine at Sears. They come in a set and are not cheap!! The steps: 1. Rip the rubber cover off the coupling. There's a metal disc inside. 2. Secure the shaft with the wrench. 3. Grab the metal disc with a plier and quickly **** it CLOCKWISE. This is to overcome the inertia. 4. If not loosened repeat steps 2~3. 5. Screw new coupling on COUNTER-CLOCKWISE. Now you are ready to make that smoothe or margarita or what have you again! Disclaimer: Kids, don't do this at home. I am not responsible for any explicit or implicit damages caused by you repairing your blender. Read manufacture's warranty policy before proceeding. Call their service center if you don't feel comfortable performing the aforementioned repair.