I have more than 1 year with my EVO 4G, and about 6 motnths ago, i have a "signal bouncing" problems, i explain. i finish a call, and the signal wipe out completly, and come back again in less than a second. i use the app Network Signal Info and appear with no signal in some areas, but the signal bar in the notification area appear with signal but doesn't make calls my phone. anyone???
If it is happening everywhere then it is more likely your phone. Unfortunately, the only way to tell if it is hardware is to wipe the software back to factory. If it still does it then your radio may be bad.
I don't see any reported network issues in the locations that you have provided. I would agree with Mr. Mcnoodlie in that since you are experiencing this issue over such a broad area of coverage that it is indeed something with the handset. I would recommend that you swing by the nearest repair center and have them do a hardware check on the device to see if your not experiencing antenna issues.
the other possible issue could be software related, the easiest way to verify this is complementing the wipe. If you are still having the issue would more than likely be hardware related.
Please note that all data will be deleted from the HTC EVO 4G as a result of this procedure. This process does NOT delete data stored on the microSD card. We recommend backing up all of your personal data before proceeding.
If you selected YES, all data including third-party applications will be deleted from the HTC EVO 4G. Once the wipe is complete, the phone will reboot to its factory fresh state.