# Troubleshooting

- [nbn Self-Diagnostic Tool](/support/services/connectivity/nbn-tc4/troubleshooting/nbn-self-diagnostic-tool.md): The NBN Diagnostics tool gives you the freedom to run tests when you need them
- [Responsibility Matrix](/support/services/connectivity/nbn-tc4/troubleshooting/responsibility-matrix.md)
- [On-site Investigation and Diagnostics](/support/services/connectivity/nbn-tc4/troubleshooting/on-site-investigation-and-diagnostics.md)