The Sprint HTC EVO 3D recently received an update and, if you’ve applied the new PRL list (preferred roaming list) you’ve might have noticed that you’re kind of stuck on slow 2G connections. Version 50580 of the PRL on the EVO 3D seems to block Sprint’s 3D EVDO thus forcing you to use the 1xRTT network.
If you experience the above and can’t/won’t wait for an official fix from the carrier or manufacturer, there’s a way to reclaim your faster speeds, given you’re an advanced Android user that likes to get his/her hands dirty. The process of reverting to the old PRL version 21081 implies that you root your phone and have access to the unique MSL code. Following the source link below you’ll find the instructions needed to get back on track or you can always wait for an official fix which shouldn’t be that far out.