My Lumia 620 has a flight mode problem, how can I fix it?

[Windows Central Question]

lumia 620 flight mode problem

Im using official windows 8.1 denim update
one day suddenly phone got hanged ..after restarting struck on flight mode !!
i tried soft & hard rest and also nokia software recovery tool .. no use of these ... i gave phone to local shop to flashing ..that also never helped me .. local shop guy telling its hardware problem ..its cost about about 800 -1000 !! help me friends ...
Thanks in advance