What could be wrong with my ZTE Z932L if it dont make a sound or don't vibrate when someone is trying to call or cant make calls on speaker phone or listen to my music on speaker phone?

look on this site:
How to easily root an Android device CNET

Are you able to hear voice of other side during a call?
first try to reboot, factory reset phone and change SD card etc as a priliminary troubleshoot.
every cell phone does have 2 speakers, one as ear piece for low sound and another for louder sound (for ringtones, music etc), google to try the code for your ZTE model's h/w responce code e.g. for all all Samsung phones it's *#0*#.
and check your speaker, If it's faulty, visit nearest service center, as it does'nt seems a firmware error.

while on call try to press the volume up

or

something wrong with your earpiece, the small speaker.

I dont know my sound is on voume 7 but if someone calls it doesnt ring or make the melody noise whenever i press a button it hasnt been doing that since the past 3 days

The earpiece of the phone is bad and it can be replace at the phone maker shop e.g. Nokia phone at Nokia world shop, Motorola at Motorola shop etc.it will be fixed there. Thanks

change the speaker

you can check if you speaker is broken by using a set of headphones. if you don't hear sound when using your headphones there is something wrong with your software settings. if you do hear sounds using your headphones you need to replace your speaker. You can buy a replacement speaker on ebay and do this yourself, of search for someone to do if for you. If you still have warranty on your phone just return it to the shop that sold the phone.

johanita - have the phone speaker replaced.

oleg83 - ear piece speaker needs to be replaced

heyari - replaced the speaker

GUEST - replaced the speaker on the phone

tina-ehmm-72 - the ringer and ear piece needs to be replaced

hashah - replaced the speaker

dear replace the speaker of ur phone in k300 the speaker and ringer are the same if u not have new speaker then short both point of the speaker to gather will be ok.