The Google Nexus 9 by HTC is a great tablet – I love mine – but it does have some manufacturing issues that seem to have been largely fixed in later manufacturing runs. Figuring out when a particular tablet was manufactured, however, is not always easy. It’s not printed on the box, unlike some manufacturers, and it’s not even apparent by looking at the serial number.
Luckily, some brilliant developers discovered exactly what logic HTC used to come up with serial numbers, and have launched a dedicated website that will allow you to find out exactly when your tablet made its way through the factory. All you have to do is type your serial number into the website listed in the source link below.
Of course, some users swear that there are no differences between different manufacturing dates, but the vast majority of people do notice some subtle if not outright changes. Personally, I suffer from squishy volume buttons, but I’ve decided to keep mine anyway.