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Troubleshooting. Introduction. This section provides you with the necessary skills to effectively troubleshoot the DIRECTV System. Objectives. Test signal using a signal meter Verify correct voltage from the IRD Test for an open circuit Test for a short circuit Field test the LNB
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Introduction • This section provides you with the necessary skills to effectively troubleshoot the DIRECTV System
Objectives • Test signal using a signal meter • Verify correct voltage from the IRD • Test for an open circuit • Test for a short circuit • Field test the LNB • Run a system test on the IRD
Troubleshooting • Identifying Symptoms • No picture on television • Searching for Satellite • Missing Channels
Troubleshooting • System Inspection • Animal chewed through cable • Cable jacket is damaged by weed-eater • Cable stapled or kinked • Improper ground • Improper electrical outlet • Improper Connectors • Damage to reflector or mount
Signal Level Meter • These 3 signal level meters are the most common used in the field today • The signal level meter reads the level of signal in the line • Advanced signal level meters like the BirdDog can identify specific satellites • In Line meters may have an option that allows you to read voltage
Quick Hit Troubleshooting • Determine the Signal at the IRD • Determine the defective component with SFSS on all odd, all even or several transponders • What is the signal level • No signal or low signal at IRD • Do a hard reboot • Check the cable connections • Read signal level at the back of the receiver using a signal level meter
Quick Hit Troubleshooting • Good signal on the meter, but not on the IRD • Check voltage out of IRD • Using a binding post adapter or a pre-made test connector check the voltage, the black lead to the shield and the red lead to the center conductor • Use VOM • Voltage should display as switching between 13 and 18 volts • No voltage or voltage not switching – replace receiver • Voltage detected but no signal level on IRD – replace receiver
Quick Hit Troubleshooting The Volt Ohm Meter • VOMs can read AC or DC voltage • VOMs can read resistance in Ohms • VOMs are battery powered when checking resistance Ω
Quick Hit Troubleshooting The Volt Ohm Meter • All VOMs have 2 leads or probes • Connecting Leads • Reading Voltage
Quick Hit Troubleshooting The Signal Level Meter • Can read voltages at the LNB loaded • This means that the Signal Level Meter reads the true voltage on the line with the draw from the LNB
Troubleshooting In Line Components • No Signal from ODU Cable • Are there other receivers on the account? • If yes, are they working? • If they are, the problem is isolated to this receiver and feed • Proceed to the multiswitch or ODU; whichever is feeding this outlet
Troubleshooting In Line Components • No Signal from ODU Cable • If you have very weak or no signal at the port, test the other ports and see if they are working properly • If the other ports are providing adequate signal but this one isn’t, replace the multiswitch • If all ports have low signal level check the input signal to the multiswitch
Troubleshooting In Line Components • Signal coming in from multiswitch is low • Common Problems • Electrical Surge • Corroded/Damaged “F” Connectors • Incorrect or Damaged Cable • Moisture Migration • Poor Return Loss • Failed Internal Parts
Troubleshooting In Line Components • If the signal coming into the multiswitch is low, go to the ODU and check the output at the LNB. • If low or no signal, look to see if there are any obstructions blocking signal • If there is clear line if sight attempt to realign the ODU to peak signal • If you can not get signal replace the LNB
Troubleshooting In Line Components • Good Signal From ODU • Test the drop to the multiswitch or the defective receiver for an openor a short • The Volt Ohm Meter • Reading Resistance • Shorts, opens and damage
Troubleshooting In Line Components • Short Circuit Test • Disconnect cable on both ends • Set multi-meter to ohms • Touch one lead to center conductor and the other to the braid. • Meter should read 0, open or infinite • A short will be indicated by a fluctuating or constant resistance
Troubleshooting In Line Components • Open Circuit Test • Remove the cables from the LNB • Short cable using 75 ohm terminator • Set multi-meter to ohms • Touch one lead to center conductor and the other to the braid
Troubleshooting In Line Components • Open Circuit Test (Continued) • Meter should read 75 ohms or greater, the longer the cable the greater the resistance in the circuit (Approximately. 1.6 Ohms per 100 feet of RG-6 • An indication of an open circuit would read 0, open or infinite
Troubleshooting In Line Components • Damaged Cable Test • Check the resistance of a terminator which should read approximately 75 Ohms: • Firmly holding the black probe to the outer case and firmly pressing the red probe to the center conductor • Once the resistance is known, connect the terminator to one end of the cable and read the resistance at the other end using a binding post adapter or an adapter you made.
Troubleshooting In Line Components • Good Signal From ODU • Consider the Voltage drop, attenuation and insertion loss • Use a signal level meter to calculate cable attenuation using a fixed scale for RG11, RG6 & RG59 Loss estimate per 100 feet at 68º F at 1450 MHz • RG6 = -7.89 • RG11 = -5.29 • RG59 = -9.82
Troubleshooting In Line Components The Signal Level Meter • Calculating cable attenuation at 2150 MHz Loss estimate per 100 feet at 68º F at 2150 MHz • RG6 = -9.69 • RG11 = -6.60 • RG59 = -12.10
Troubleshooting In Line Components • Good Signal From LNB • Calculate the signal loss between the ODU and multiswitch • Consider the cable loss and insertion loss of other component • Look for defective components • Check each device to determine the signal level coming in and out • If you suspect the drop is defective test for a short or open
Troubleshooting In Line Components • In Line Devices • The cable used for a DIRECTV installation should always be approved RG6 coaxial. • Signal Loss: • Impact at 950 to 1450 MHz • 7.89 dB per 100 feet • Impact at 250 to 2150 MHz • 9.69 dB per 100 feet • Voltage drop per 100 ft at 18 volts with 300 milliamp draw • .48 volts per 100 feet
Troubleshooting In Line Components • Power Loss - dB • Some Signal Meters on the market can show you the dB values as well as signal strength • Generally you will see dB values at the ODU around - 32dB • The DIRECTV receivers can still show picture at levels no less than - 60dB • F-Connectors give you - .5dB loss per • F-81 barrels give you - 1dB loss per
Troubleshooting In Line Components • Good Signal From LNB • Calculate the signal loss between the ODU and multiswitch • Consider the cable loss and insertion loss of all other components. • Is the loss greater than your calculation? If so: • Is the cable all RG6? • Are all components rated for the frequency spectrum you need for the receiver
Troubleshooting In Line Components • Good Signal From MultiSwitch • If the drop feeding the multiswitch now has good signal at that location check the output of the switch again • If the drop feeding the multiswitch has no signal at that location and there are no in-line components replace that cable run • You can run a temporary drop to confirm a cable problem • If there are any in line components test the input signal and output signal of each to determine which has failed • Replace any defective components or cable and reconnect the feed to the switch
Using Test Equipment • The scale on the unit enables you to determine the status of the outlet Open Ground Open Neutral Open Hot Hot/Ground Reversed Hot/Neutral Reversed Correct
Summary • Now that you have completed this section you should be able to: • Test signal using a signal meter • Verify correct voltage from the IRD • Test for an open circuit • Test for a short circuit • Field test the LNB • Run a system test on the IRD
Exercise • Hands-On • Station #1 Verify Voltage & Signal Strength • Station #2 Open and Short Circuits • Station #3 Troubleshooting Wall