My sony ericsson xperia lt 29i hayabusa shows phone crashed

[Mariomuco]

hi i have a sony ericsson xperia lt9i hayabusa.when i turn on my phone sometimes shows in the screen phone crashed and shows there a round circle loading and then shows hardware watchdog.sometimes when i remove battery its turn on but when i lock the screen and try to open again its not turning on and gets stucked in black screen .Please how can i fix becouse im trying for days with all of possible solutions but anything.

[Phy]

Try repairing it with Sony PC Companion.
http://support.sonymobile.com/us/tools/pc-companion/

[Phy]

If that doesn't work then contact Sony Xperia Support.
http://support.sonymobile.com/global-en/contactUs/

[Mariomuco]

But when i connect to sony pc companion and start the update there shows that update service cannot find a software for your phone .I put 4.1.2 firmware with flashtool but some apps not opening ex.walkman,camera,messaging etc and wifi not opening .please give me a solution how to fix these . thanks for your reply