If the dive computer was working properly before the battery went dead, there is an extremely high success rate (99% +) with changing the battery. Occasionally, a dead battery is left inside a watch or dive computer for a long period causing corrosion of the electric contacts beyond repair. In other occasions the computer itself or the pressure sensor has failed and the computer cannot be repaired by us. If you have already removed the battery yourself, we will attempt the repair; however, the success rate is somewhat lower. In case we cannot get the watch or dive computer to function properly we will only charge you for return shipping.