I have the same problem with a Jiayu G2S MTK6577T phone. It's Android 4.1.2, with Skype 18.104.22.168403. If I make a call I can hear the other person but they can't hear me. If I use the Skype Echo/Test Sound service I can hear the voice telling me to speak until I hear the tone. I speak until I hear the tone, but when the message is played back all I hear is a buzzing sound.
There's no problem with the phone's microphone as it works fine when I make calls from the phone itself.
I had the same problem. The newest version of Skype has problems. I fixed it by installing an older version of Skype and refusing any updates by going to Google Play and choosing "Do Not Auto-Update" option for Skype so the newer version doesn't get installed. My microphone now works and I can hear sound again.
If your mic works with other apps like tango or simple calling then its not your MIC issue its your skype version, actually NOIR A60 comes with an old version by default and if you update or install a new version from Google play then it may not work.
please find a link below of Skype Old version for QMOBILE A60 which worked on my A60
I have Jiayu G2S (MTK 6577) phone. Half a year ago Skype worked well, then there were some updates and from 4.0 version skype doesn't work on Android. While echo testing I can hear only bzzzzz. Tried some of fixes mentioned here in this thread, what helped me was a downgrade to 3.2 but even I can use skype only in speaker mode, the ear mode is not working anymore (only bzzzzz sound). Other apps using microphone (CSipsimple, Duolingo, etc) didn't even mentioned any problem but Skype is full of bugs for months. This thread is slightly becomming one of the longest, but Skype team doesnt care.