The repair of aircraft components is slightly different from a complete overhaul, as the workshop needs only to determine what causes a given defect, rectify that defect, run some bench tests and release the component back to service.
The trouble shooting procedures are generally available in the CMM or the CRM (component repair manual). Therefore, in most common scenarios, the procedure is as follows:
Check the documentation for a trouble shooting (T/S) procedure applicable to the given defect symptoms
Carry out all tests in accordance with the procedure
Determine the fault
Eliminate the fault in accordance with an appropriate procedure from the CMM/CRM
Do reassembly tests and release the unit
As simple as this may sound, there is something that every operator or airworthiness provider needs to understand and remember:
Whenever a component is torn down (“opened up”) in a workshop, it is the workshop responsibility to assess its general state (not only with respect to the reported defect, but as a whole). This means, that a simple defect may end up requiring even a complete overhaul if, after the components is opened, it turns out that several parts and subassemblies need replacing due to excessive wear and tear. This always increases costs and is very difficult to plan for because, for parts which are not hard time controlled, it is almost impossible to assess their condition without bench testing them at least.