Thank you Miss Portia for your suggestion, but I do not have a flashing red light, what I do have is the following: I had my Xbox working just fine, there came a notification of a mandatory update when I tried to connect to Xbox Live. The update was installing and a blackout happened. After the power came back, I turned the Xbox back on and no video was shown on my TV screen and the green dot turned red after a few seconds. Is doing this since then, I follow all the tips that I found and the ones all the people here suggested and I had no luck what so ever. I'm afraid I should send it to repair, the only problem is that were I live, there is no official service for Xbox systems, I have to ship it to the US, and that will cost me almost as much as a new XBOX. And my great frustration is the fact that I can believe Microsoft has no software tools to repair something like this, that actually could happen to anyone.
Sorry for the long response, and thanks again.