An IPhone or IPad can develop all kinds of problems and faults due to being dropped or knocked, but in most cases the fault can be repaired.
IPhone and IPad logic board repair is required when a fault / problem is beyond simply changing a component. When micro-components on the logic board need repairing or replacing due to deterioration, perishing, water damage or from being blown or knocked off the logic board in error.
Logic board repair should only be carried out by a specialist logic board repair technician. In many cases repair centres when faced with a logic board repair will tell you that IPhone / IPad is beyond repair, this is simply not the case.