Troubleshooting Digital Television Service Introduction

What are some set-top box (STB)-related troubleshooting calls that can be avoided with customer education?

VOD recordings Blocked IR detector Overheating STB

Which of the following is data in an out-of-band data channel? Choose all that apply.

STP application, STB authorization, EPG

Why does troubleshooting of digital TV (DTV) service logically revolve around the digital set-top box (STB)?

Because the digital STB functions as a gateway, providing DTV service to customer's TVs and other devices, it is logical that troubleshooting of DTV service revolves around the digital STB.

When replacing a splitter to resolve a digital TV (DTV) service problem, what does confirming the splitter output levels before attaching the output connectors do?

Confirmation reinforces the technician's confidence that the problem will be resolved by replacing the splitter.

During which step of the six-step troubleshooting process for a digital TV (DTV) service problem are quadrature amplitude modulation (QAM) channel measurements typically taken?

Diagnosing symptoms.

What prevents authorization of some digital set-top boxes (STB) and ordering of video-on-demand (VOD) content?

Digital TV (DTV) services, such as VOD and authorization of some STBs, require communications with the headend via the RF return path.

What is included in digital set-top boxes (STB) to provide product engineers with information pertaining to the STB operation and the channels coming into and leaving the STB?

From the beginning, diagnostic screens have been included in digital STB to provide the product engineers with information pertaining to the STB operation and the channels coming into and leaving the STB.

After a digital TV (DTV) service problem has been analyzed and possible causes considered, what is accomplished by isolating the various network elements?

It narrows the scope of likely problem sources.

How are the functions of a digital set-top box (STB) like those of a personal computer (PC)?

Many of the functions of a digital STB are like those of a PC with memory for boot-up software, an operating system (OS), graphical interfaces, middleware, and applications software.

Because the spectral density of a quadrature amplitude modulation (QAM) channel is much higher than that of an analog TV channel, what is done to ensure equal power in all channels in a network with analog and digital modulation channels?

Operate the analog TV channels at higher amplitude level than the QAM channels.

When troubleshooting a digital TV (DTV) authorization issue, what can be verified using the set-top box (STB) diagnostic page?

STB reception of authorization message data.

Which type of set-top box (STB) operates more like Data Over Cable Service Interface Specification (DOCSIS) cable modems with return channels on the same frequencies used for cable modems?

STB with DOCSIS Set-top Gateway (DSG) client software and embedded DOCSIS modems.

Which of the following characterizes the successful troubleshooter?

Someone with an inquisitive and relentless desire to solve and fix problems.

Which of the following digital TV (DTV) trouble calls could have been avoided with customer education about the product?

The digital set-top box (STB) overheats.

What must a technician be aware of when analyzing a digital TV (DTV) problem?

There is frequently more than one contributor to a specific DTV service problem.

T/F: An output level that is at, or near maximum from the STB can indicate excessive loss in the drop system.

True

T/F: Theset-top box (STB) controller in the headendset-top box (STB) diagnosticcan be used to verify set-top box (STB) connectivity with the headend.

True

T/F: Theset-top box (STB) controller in the headendset-top box (STB) diagnosticinstructs the STB to adjust it's return channel amplitude levels.

True

What will you use to diagnose a digital television (DTV) issue?

STB Diagnostic -receipt of STB -reception intact EMMs -return channel frequency power level -QAM channel STB is tuned SLM -QAM channel parameters - QAM measurements in field

What does a set-top box (STB) diagnostic page of a quadrature amplitude modulation (QAM) channel showing signal-to-noise ratio (SNR) near or below 30 dB indicate?

The QAM channel quality is on the edge for reliable reception, and the source of the problem is likely in the distribution network or customer premises.

What digital set-top box (STB) element sometimes causes the customer to take self-education of the STB features, capabilities, and limitations for granted?

The customer-friendly electronic program guide (EPG) user interface of digital STBs can cause the customer to take self-education of the STB features, capabilities, and limitations for granted.