I don't use a 5230 , so this is a try . Did you the reflashing of the firmware by OTA (over the air) or using NSU (Nokia Software Updater) on PC/Mac ?
As a firmwareupdate is actually also a Hard Reset , I suppose you have a Backup of your Personal data .
Try the same firmware reflash again using NSU , with battery full or device connected to the charger .
I suppose you don't have a homescreen to dial the hard reset code *#7370# ? As many users of 5800 and N97 do a Hard reset after firmware-update , to get rid of unwanted data/software .
When the phone doesn't react , you can try the Vulcan Death Grip . For the 5230 I don't know , but for N97 and 5800 it's done like this : http://www.allaboutsymbian.com/forum...ad.php?t=86049
Hopefully you can figure it out . Still you could visit a Nokia Service Point .
thanks man, but i did it on my own.
I first download Navifirm (a software for downloading Firmware files without NSU)
then i downloaded JAF 1.98.62 and then usingf dead USB i reflashed the phone and again updated through Nokia NSU(to ensure i have the Original Nokia Software).
Now my phone works fine!!Thank You!