After cleaning my blender the base was screwed on cross threaded. I can't unscrew it to fix it. What should I do?

I am no expert on food blenders but look between the teeth of the drive gear. Some models have a tiny grub screw hidden between the teeth as a locking pin into the spindle.
unscrew it until it just sticks out. Don't take it all the way out as your guaranteed to drop it and lose it. (Yes, I've done that!). Other than that it could be a circlip inside the top or a tiny nut/screw under a small covering cap. Some are even a 'push on' fit. I DON'T recommend just yanking on it. You'll break it completely that way.
Some blenders, especially the cheaper ones, are deliberately designed not to be repaired so you have to buy a new one instead.
I hope this helps

Oh some of these answers... the most common issue with blender is that the removable blade unit starts to jam. So :
1. unscrew it, clean it and make sure it turns easy
2. open the unit and replace the fuse that blew up because turning the blade became too hard.
Voila

Yes its easy to take the Magic Bullet apart.

1. First pry out the 4 black rubber feet on the base with small screwdriver and unscrew the 4 cross head screws revealed below.

2. Remove this black base to reveal the inner black base Unscrew the cable clamp - 2 screws and the 3 screws that retain the remaining black base to the body of the bullet - slide it off over the power cable.

3. Turn the bullet the proper way up and pry out the 3 white rubber bumpers with a screw driver blade that are set inside for the cup to rest on - each is located with two rubber pins. Once all 3 are removed you will reveal 3 more cross head screws - these countersunk - remove all 3 and then the internal motor will be free to lift out through the top of the Bullet casing.

4. Its possible to slip out the 3 white plastic sliders - taking care to note how they seat each on a small spring to cleanup both the slides and the sliders.

To re assemble step by step in reverse - noting to align the motor cable with the cutouts on the bullet base.

I posted the reply pasted below on how to take the Bullet apart - really not difficult once you know where the hidden screws are apart. Once apart it easy to see where the power cable terminates and should be easily possible to connect in a new cable in its place.

Yes its easy to take the Magic Bullet apart.

1. First pry out the 4 black rubber feet on the base with small screwdriver and unscrew the 4 cross head screws revealed below.

2. Remove this black base to reveal the inner black base Unscrew the cable clamp - 2 screws and the 3 screws that retain the remaining black base to the body of the bullet - slide it off over the power cable.

3. Turn the bullet the proper way up and pry out the 3 white rubber bumpers with a screw driver blade that are set inside for the cup to rest on - each is located with two rubber pins. Once all 3 are removed you will reveal 3 more cross head screws - these countersunk - remove all 3 and then the internal motor will be free to lift out through the top of the Bullet casing.

4. Its possible to slip out the 3 white plastic sliders - taking care to note how they seat each on a small spring to cleanup both the slides and the sliders.

To re assemble step by step in reverse - noting to align the motor cable with the cutouts on the bullet base.

It should release with a 1/8 twist in the counter-clockwise direction.

I tried the vinegar thing but it didn't quite work. We blended some smoothies with yogurt and it leaked through the bottom. No big deal, we tightened it up. We didn't clean it immediately. By the time we went to clean it, it was stuck. The vinegar didn't work, tried baking soda with vinegar, didn't work. Finally we ran the bottom underneath hot water for about 5-10 minutes. Finally after one strong turn the bottom came off. We have an oyster, the base can be used as well to take the bottom off but it turns counter-clockwise.

Take a look on amazon here Amazon com magic bullet blender parts. I hope it was helpful. enjoy

Remove the base the screws are under the rubber feet,on top of the machine there are three screw caps remove these with a bradel, unscrew screws with large torx screw driver, remove spindle anti clockwise by locking out fan at base. for all Robot coupe parts go to http://www.catering-machines.com/