Head phone not working...

Question

head phone not working after i update to yosemite , I tried with different headphones but it didn't work. I am able to control the volume with the head phone buttons.

Answer 1

Take each of the following steps that you haven't already tried.
1. If your model has an audio-out (headphone) port, and a red light is coming from it, the internal switch is stuck in the position for digital output. You may be able to free it by inserting and removing a mini-stereo jack of the proper size. Inserting any kind of tool in the port may cause damage that won't be covered by your warranty.
If there's no red light, the switch may still be stuck in the headphone position. Try to free it the same way.
2. From the menu bar, select
 ▹ System Preferences ▹ Sound ▹ Output
Check the settings. The internal speakers should be selected as the output device, the Mute box should not be checked, and the volume slider should be at least halfway to the right.
3. Boot in safe mode. It will take much longer than usual. You don't have to log in; just reboot as usual when the login screen appears. Note: If FileVault is enabled under OS X 10.7 or later, or if a firmware password is set, or if the boot volume is a software RAID, you can’t boot in safe mode.
4. Reset the NVRAM.
5. Reset the SMC.
6. Reinstall OS X after backing up all data as a precaution. You won't need your backup unless something goes wrong.
7. Make a "Genius" appointment at an Apple Store.
Back up all data on the internal drive(s) before you hand over your computer to anyone. If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to bare metal from any of them.) Don’t erase the recovery partition, if present.
*An SSD doesn't need to be zeroed.