[Q] unable to flash stock,install rom,and struck at recovery loop topic

anyone pls.i need a help seriously..i installed blisspop 1.8 in my lg f240L.everythng worked fine.but i found that my call voice quality was very low and thought of going back to my old rom VUPMP.so aas i read in some sections for gng back frm cm12,shuld go from philz recovery,i did that.but unfortunately after installation of that rom my phn is showing only lg logo.i did hard reset by holding power down+home button+lock button.after that im getting a recovery loop.then i decided to flash a stock rom using lg flash tool.but in download mode its showing error in connection between cellphone and pc even though the usb cable was good.so now i got struck.please anyone solve my problem,with a detail procedure.ill be very thankful to u..please help me...