A defective amplifier is only one possible cause of a school announcement system failure. The existing speaker cabling, loudspeakers, connectors and zones also need to be considered before a replacement amplifier is connected.
State the assumption clearly
If the quotation reuses the existing speaker infrastructure, it should say that the cabling and speakers are assumed to be serviceable. This keeps the replacement scope clear and prepares the client for further investigation if testing reveals another fault.
Test zones before handover
A school PA system may serve several areas or zones. Each zone should be checked for continuity, shorts, output and intelligible speech. A new amplifier can be installed correctly while a damaged route still prevents part of the system from working.
Allow for the real site condition
The final requirement may change when the existing infrastructure is tested. Additional speakers, cable repairs or fault-finding may need separate approval. That is better handled openly than hidden inside an unrealistic replacement allowance.
DG Technologies approaches commercial AV and PA systems with the same practical discipline used in boardrooms: understand the existing paths, test the system and document the result.