i have a rooted sony ericsson xperia play r800at from AT&T. i was changing the font of the system with an app and it needed to reboot to apply changes. as it shut off it turned back on and showed the "SONY ERICSSON" logo and then turned off and did the same thing. i left it on and the cycle kept continuing and it has not booted up since. please help?

NOTE: my phone for some reason does not go into recovery mode. i've tried everything to get it into recovery with no avail. many thanks