Try to do these solutions.
K750i, W800i White Display Lcd Problem

Alkesh :

Sony k 508 ear pice slow sound speaker ok any help possible

Sony Ericsson K500i, K508i Speaker Earpiece Ways Problem
there your go k500i speaker problem volume too low

prabath :

Regarding k 750i display problems.(when using wething 5,6 hours it display gets white. seems to be mother bord problem. ) pls help me.
thanks.

there you go
http://repairmobiles.saaqi.com/k750i-no-lcd-display-problem/

Jasoliya :

K310i ME mic ka problem he mic chnj karta hu fir bhi chlu nhi hota he pls is ka koy pic hoto bata do

http://repairmobiles.saaqi.com/k310-mic-microphone-ways-problem/
there you go brother

ayaaz :

my sony cell k310 joysticks porblm i need help me joysticks ware

K310 Mouse Joystick Ways Problem

there you go brother