"Meizy MX3 top speaker won't work when calling someone."に関する回答Since you can still hear the other person when using speaker phone, chances are it isn't a simple volume error. I would still check to make sure that the in-call volume is set to max so you can be certain that nothing is coming out. Also, it wouldn't hurt to quickly reinstall your devices software to make sure that the loss of in-call volume isn't due to some unknown software error. If none of that helps, the speaker in your phone is probably broken, and will need to be replaced.
"Camera won't auto focus."に関する回答Have you ruled out any potential software errors? Try reinstalling your device firmware to make sure that the loss of auto-focus isn't software related. You may also want to try checking the settings in your camera app. If an auto-focus setting is present, make sure it's checked. If none of that helps, then sadly, the camera in your device is broken, and will need to be replaced.
"Touch screen won't cenors well after being dropped"に関する回答Sorry to hear about what happened to your phone. Are you positive that the error you're experiencing is due to dropping the phone? You may want to try reinstalling the device software to rule out any software errors before you decide to do a repair. However, if you physically damaged your device, and now the touchscreen isn't working, chances are you damaged the touch screen digitizer. Sadly, the display and digitizer are a single assembly, so you'll need to replace both to fix your device.