dead k810i not detected by computer

my k810i shows white screen continuously when i switch on the mobile. and from the tutorials in the web i found out that i have to flash my mobile. to do this, i installed the usb flash drivers in my computer. two three days ago it had detected my mobile. nowadays, it doesnt detect my mobile. help me please.... i am running in xp.

first clean the system connector, reinsert battery, connect usb while holding 'C' button on phone

but it is not working either. if it had been due to defect in system connector, then why after some time of connecting the mobile to pc, the white screen again appears? really need to get out this problem...