T-Mobile (NASDAQ:TMUS) is preparing to report earnings this week. The Magenta carrier put up solid results last time around, gaining postpaid subscribers for the first time in years. Last quarter, it added nearly 700,000 postpaid subscribers to its ranks, which are a valuable segment of the market. T-Mobile will need to follow up again if it hopes to maintain the momentum it's built.

Over the weekend, T-Mobile had some missteps related to Apple's iPad Air launch. The company mistakenly said it would cost $10 per month for "free" data, an accounting error that was soon rectified. However, only subscribers paying at least $20 per month can take advantage of T-Mobile's free financing plans -- a fact that it neglected to clarify ahead of time. Much of T-Mobile's turnaround has been predicated on greater transparency and better communication with customers. One weekend of missteps will likely be forgotten, so long as it's not part of a larger trend.

In this segment of Tech Teardown, Erin Kennedy discusses T-Mobile's upcoming earnings with Evan Niu, CFA, our tech and telecom bureau chief.