V3x problems

my phone oftens goes blank,then screen turns white,then it continues doin this,even when battery is full.ribbon was inspected and found to be faultless.whenever i open flip to answer call it shuts off,or press a button to answer a call it shuts off,and goes through the whole blank then white process again.also.whenever i try to playback video that ive recorded theres this loud annoying buzz which drowns out the audio,even for first few seconds when answering call party on other end says its annoyingly loud.please help me. my phone no longer communicates with the phone tools software on my pc either.please help me,at wits end.