HELP Lumia 920 not functional

[hyperthermia]

its been 4 months now and im taking this as my final step before i sell my lumia 920. i love the phone but it has been useless for months now.
my 920 is unlocked international variant
after the i downloaded access point and extras+ my connectivity got unstable. no signal even for sms 50% of the time, multiple updates has not fixed this, even hard reset failed.
updated to portico and now amber still broken.
after 2 days of amber my phones sound and vibration not working. it cannot play music fr xbox. i can see videos time progressing but music is still 0.00 although it shows its playing
soft reset done. not working. im about to give up now.

my plan is to flash the phone to its original state. help me please
then do ota update to amber

ive checked threads but mostly for att variant, how about for international one?

my 920 has become my music and social network gadget after it lost its signal. now its useless. i love wp and lumia but things has been very frustrating. please help me

 

[hipporama]

It looks like you have a bad piece and I doubt any number of updates/hard resets is going to help. You should have exchanged it while you could.

 

[AlexRodriguezNY]

Contact Nokia I think you still have warranty if you have it only for four months. Explain to them and they should guide you on how to proceed.Maybe they tell you to send it to them , maybe they replace it if they can't fix it.