Panasonic KX-T336 System Reference Manual page 1448

E. Troubleshooting Guide
1.00 Introduction
This subsection uses system troubleshooting flow
charts to guide the service personnel in efficient
and systematic testing and fault location.
The system troubleshooting flow charts provides
service personnel with a step-by-step sequence
to use for system evaluation. Isolated steps in a
flow chart should never be used out of context,
since any step assumes that proper results were
obtained on all previous tests.
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