@beruk you did not tell us what you phone does or does not do. You also need to tell us what was fixed the second time after it fell. It could be a power situation and you want to check your battery, connectors and see if your phone charges. Replace the battery just to be absolutely certain that you have a working one. ZTE does not offer their schematics to service manuals to the public. So you may have to find someone that specialized on ZTE phone board repair if the issue is on the board itself.