whatswrong with my bb 7290?

[maintenancemanny]

I recently picked up a 7290 from a wanted ad.I really like this bb but I get no service anywhere or anytime? The only thing I notice is that if I leave set for 5 -6 hrs it picks up signal,but soon as I try to use it ,it goes away and never returns,,is there anythingI can do to regain signal strength?HELP!!!!

[wandiweah]

1. try turning of wireless for at least 30 seconds
2. try a battery pull - leave the battery out for at least 30 seconds
3. contact ATT