what i did is buy a new battery n the symptom changed, when i pressed d power button, the phone only vibrates and just that, no boot screen or whatsoever. clearly a different symptom with the other battery.
currently i'm trying to charge both the battery and tried to reboot the phone with all the methods tried in this thread. hopefully i can solve the problem by myself before sending it to the shop.
no more warranty anymore by the way...
update : currently i'm charging the phone with the original battery and the red led keeps blinking every second but the other battery doesn't have any led blinking or whatsoever and seems not charging at all. the weird thing is the new battery that i bought is alr been tested and works damn fine with other xperia x10 model
update 2 : i've already leave the phone to charge with the new battery and currently both battery when inserted gave the same red led blinks, won't even boot up. at this point, my only assumption would be the usb charging port is somehow broken and no other choice but to send it for repairs...
i appreciate it if someone have other alternatives for me to try but fyi my comp won't even detect the phone even in SEUS (latest version)