[Q] Frequent Restarting problem of my LG F240L topic

I have Lg f240l.it frequently restarts itself 20-30 times a day.i even flashed it many times using lg smart flash tool.but no change.but i installed blisspop rom and it worked fine for me(sometimes not recheable msg when someone tries to call me) but i reverted back to stock due to voice in call prblms..the restart prblm is embarrassing me, when im browsing internet or chatting it suddenly stops and restarts itself,sometimes poweroffs.i gave it to lg care and they said everythng is fine(hardware,power buttons and batter) but i thnk the prblm is with software.so can anyone facing/faced the same issue and found a sol?pls clear and solve my prblm....does giving my mbl to 3rd party repair shop for flashing clears this?suggest me pls!!!!