NEW YORK — T-Mobile USA resumed selling Sidekick phones Tuesday, more than a month after a server meltdown at Microsoft Corp. caused contact numbers, pictures and other personal information to disappear from many of the phones.

In the intervening time, Microsoft managed to restore most of the missing user data. T-Mobile provided $100 gift cards to affected customers.

The Sidekicks listed on T-Mobile's Web site are now slightly cheaper. For instance, the top-of-the-line LX model is now $150, down from $175.

Unlike most phones, Sidekicks can lose all personal data when the batteries run down. The data is then restored from Microsoft's servers over the wireless network. When the servers went down in early October, Sidekicks lost e-mail and Web access, and phones that ran down their batteries or were reset lost all personal data.

Microsoft bought Danger Inc., the maker of the Sidekick, last year in an attempt to revitalize its own "smart" phone software portfolio. T-Mobile is part of Deutsche Telekom AG.