K800i problems plese help!

ive got a k800i that now will not turn or or charge ive tryed the 2+5 buttons when u connect it so the sony update, it does kno the phone is the but always fails doing the updade, it sometimes turns on only showing a white screen, ive been told its a firmware or erom problem, id like to know where to go and what to do to fix this gem of a phone ive also got the c905, has anyone had problems with these yet???? mine is still working awsome thanks...... :confused::confused::confused: