Cable and DSL customer equipment troubleshooting
Find out whether a home's broadband problem is the line, the inside wiring or the customer's own equipment: coax, splitters and F-connectors; reading modem signal levels against the provider's spec; DSL demarcation, filters and inside wiring; and isolating the modem from the router.
- Level
- Beginner
- Length
- About 55 minutes
- Contents
- 3 lessons · 1 video · final exam
- Status
- Published · updated 1 Oct 2026
Skills you'll practise
- Explain the roles of the modem (or ONT), router and Wi-Fi in a customer's setup
- Find coax faults: splitter loss, open ports, loose or damaged connectors
- Compare modem signal readings with the provider's published spec
- Use the DSL demarcation test jack and filters to separate line faults from inside-wiring faults
- Isolate a fault step by step and explain the result to the customer
Course outline
- 1.Cable and DSL customer equipment troubleshootingVideo · 2 min
- 2.Modem, router, Wi-Fi: who does whatLesson · 15 min
- 3.Cable (DOCSIS): coax, splitters and signal levelsLesson · 20 min
- 4.DSL: demarcation, filters and inside wiringLesson · 18 min
- 5.Cable and DSL customer equipment troubleshooting: knowledge checkKnowledge check · 30 questions
- 6.Cable modem drops every eveningScenario
- 7.Final exam9 questions · passing it completes the course, so people who already know the material can test out
Sources it draws on
The lessons and questions are written from these references, so learners can go back to the original.
- CableLabs DOCSIS 3.0 / 3.1 specifications (physical layer and cable modem operation)
- ITU-T G.992.5 (ADSL2+) and G.993.2 (VDSL2)
- NFPA 70 (US National Electrical Code) Article 800-series: communications and CATV grounding and bonding (US example; follow your local code)
- General ISP field practice
See it with your own jobs and topics
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