Dell Streak 7 (4G) only connecting to EDGE ..

[corrupt81]

Picked up a used T-Mobile branded Dell Streak 7 off of craigslist, took it to a T-Mobile store got the sim card and had it activated on the 2GB plan.
Get it home and it only connects to EDGE! Very slow speeds. T-Mobile phone in same house gets 4G speeds.
The box of the Streak 7 also says "4G capable".

Any ideas why it might only be connecting to EDGE?

[Scottish Skyedance]

Go to Mobile Networks setting and see is "GSM only" checked or selected; in addition, if you're able to use "WCDMA only" mode, use it.

[corrupt81]

Thanks, that did the trick. It was set on "GSM only" switched it to the "WCDMA" only and it's picking up 4G now.