There is no after sales service from Onda. You are at your own. My dual boot Onda air 919 works fine but the Lollipop 5.1 does not work with Google play services or Google Play Store. ( I have installed Aptoid to be able to install and run other applications). The Onda people refused even an advice for fixing the problem. They told me to ask the re-seller! As expected, the re-seller is unable to advise and of course never replied.
Yeah , no Google Play. They put that it wouldn’t install after I purchased and kept giving the run around about this and that … I gave up and only run Windows 10 on it which is nice … But wanted a dual OS system ?