hi guys, im having real difficulty fixing this iphone 5C, the ear speaker isnt working so naturally i thought speaker stuffed with dirt and replaced it. this didnt fix the issue. then i replaced the flex cable underneath the speaker. still not working. then i made sure the contacts were clean and touching eachother perfectly. still no noise from the speaker. can anyone help me please? is it logic board related? a very strange issue which i have exhausted all repair scenarios. thank you guys so much in advance :)