Unsolvable cube or an Outdated algorithm?

[auheart]

I have been using this particular cube for a while, and I was able to solve it in under 2 minutes on an average.
From the past two days, I'm not able to solve it, though I apply the same algorithms i used to apply.:confused:
I can go about solving the whole cube normally, i.e. the cross,the corners, the second layer. But when i came to the third layer, I could only come up to getting the cross. But after that, the part where i have to get the yellow corners facing back on top to the yellow layer (orienting the top layer), I apply the algo (R D' R' D)*2 while holding the cube such that the yellow part i need to move to the top is at the back-right-top corner.

I certainly think there must be a logical explanation to why, suddenly an algorithm ceased to apply. I used the same one a million times before successfully. This is kind of a big problem for me, because cant go to bed leaving an unsolved rubik's cube(talk about strange OCD's)

Every suggestion helps

 

[sub_zero1983]

take it apart then re-assemble it in the solved state. Then scramble it and try a few solves.

 

[JBCM627]

If you don't know how to determine if its solvable, you can always just take it apart and put it together solved. Then re-scramble.

Edit: Darn, beaten to it...

 

[MTGjumper]

You might be doing the algorithm incorrectly, or the cube may indeed be unsolvable. Without a description of the orientation of the corners (or a picture) I can't say for sure which yet.

 

[auheart]

I am pretty sure I'm getting the algorithms just right! Because they come very naturally to me as I've been solving them for a while now.
I will try my best to describe what it looks like. The bottom face(white) is solved the second layer is done too, I have made a yellow cross on top and I have oriented the edges. But none of the corners are not in place. If i hold the cube such that yellow face is on top, on yellow sticker faces me directly and lies at the right, one is behind facing right, and two at the left face at each end.
Actually it doesn't matter because no matter what it looks like the algorithm ain't working. Its just strange! Does anyone else use the algorithms I have been using? Do you guys face any problems?

 

[dbax0999]

It looks like your cube is unsolvable.
http://www.speedsolving.com/wiki/index.php/OLL
Take a look at the first 7 diagrams. Imagine the grey is yellow. If the top layer does not match one of those diagrams it is unsolvable

 

[josmil1]

Well wat algorithms are u usin in the first place since u havent stated that yet??? I'm assuming by your description that you are either at OLL 21 or OLL 22 which one does it look like?

 

[auheart]

Darn it! none of those match with mine!...How do you think mine became like that? Can that happen?

 

[qqwref]

It looks like one of the corners got twisted clockwise. If your cube is a bit loose or you forced a turn at some point, this may have happened entirely by accident. It's happened to me several times and I have cubes where it's easy to twist a corner by hand. Since the cube can't be solved, I suggest solving all corners but one and then just twisting the last one in the right direction. (If it's taking a lot of force to do this and you're worried about damaging your cube, turn the top layer 45 degrees and pry one of the adjacent edge out. Then it should be much easier to twist the corner, and you just need to put the edge back properly to finish.)

 

[Raffael]

..
I apply the algo (R D' R' D)*2 while holding the cube such that the yellow part i need to move to the top is at the back-right-top corner.
..

Every suggestion helps

Hmm, either your cube has been taken apart and put back together again wrong or you are rotating the whole cube after orientating the first corner instead of just twisting the U layer until the next corner is in back-right-up position.

 

[auheart]

Yeah well I figured out the problem, I remember taking it apart to put some lubricants and I put it back in a random fashion cause I really didn't think it was a big deal.
Anyway I pulled them apart and put em back together the right way and now I'm able to solve the cube again!
Thanks a lot for the help