Thanks for the info DanCLE.
This phone was brought from Europe to South America so I don't have any garanty.
I loaded the new OS and it worked for two days flawless, than some keys of the keyboard got frozen and the whole thing got back to where it was before.
I have the strange idea that it has to do with the video card because I get screenshots of a working phone with JL-Cmder but see the TV screen in white.
I will search for a repair guide to open the phone and check for loosen connections as I have nothing to lose.
I will post results if there are any.