Professional assessment and information boundaries

13.1 Why visible symptoms are not diagnoses

For that reason, this guide does not associate individual symptoms with tests, components or corrective actions. It does not include fault-finding sequences, incident-handling steps or product-specific interpretation of status information.

13.2 Scope deliberately excluded

The following subjects are outside the scope of this guide: fault diagnosis; opening cabinets or modules; electrical or electronic testing; software or controller configuration; calibration; cleaning; component replacement; repair; refurbishment procedures; and maintenance schedules.

Those activities depend on the product family, installation, manufacturer documentation, safety arrangements, warranty position and the competence of the people carrying them out.

13.3 The role of professional assessment

Professional assessment brings together safe access, system knowledge, appropriate test equipment, manufacturer information and an understanding of the complete installation. Its purpose is to establish evidence and select an authorised course of action without creating additional risk or masking the original problem.

This chapter is therefore limited to explaining why specialist assessment is required; it does not tell a reader how to assess, maintain or repair a display.