Troubleshooting Preamplifier Connections and Voltages (CM-7777v3, CM-7778v3 & CM-7778HD)

Preamplifier Connections and Voltages for the CM-7777v3, CM-7778v3 & CM-7778HD

The following is the sequence to connect the CM-7777v3, CM-7778v3 or CM-7778HD into your system.

Your Antenna>Short coax cable to the CM-777X Input Port>Output/Power Port from CM-777X connects to the long coax cable going into the house/structure. Then the long coax cable enters the house/structure and connects to the Power Inserter TO AMP port From the power inserter TO TV port, is connected to a coax cable that goes to a TV or to a splitter.

The 3rd coax port on the CM-7777v3, CM-7778v3 or CM-7778HD Power Inserter labeled DC IN is connected to a coax cable that is in turn connected to the power supply adaptor that plugs into the wall outlet.

Voltage readings are taken while the CM-7777v3, CM-7778v3 or CM-7778HD are not connected to the long coax cable that goes down into the house. The short coax cable from the antenna can remain connected to the preamplifier Input. The CM-7777v3, CM-7778v3 or CM-7778HD all use the same 12VDC Output power supply. When testing for DC voltage you should read about 13.2VDC at the end of any cable that connects to the output of the power inserter TO AMP port. The 12VDC Power Supply has a green power light on it.

CM-7777 & CM-7778 Came with a 15VDC Output power supply. When testing for DC voltage you should read about 21VDC at the end of any cable that connects to the output of the power inserter TO AMP port. The 15VDC Power Supply does NOT have a green power light on it.

NOTE: Earlier model Titan 2 preamplifiers CM-7777 & CM-7778 were shipped with 15VDC power supplies. The preamplifiers have a very light grey housing. Currently the CM-7777v3, CM-7778v3 & CM-7778HD are shipped with 12VDC power supply. Both are equally correct.

Additional power supply troubleshooting: The 12VDC supply for the CM-7777v3, CM-7778v3 & CM-7778HD has a constant green power light when connected to the wall outlet and operating normally. The green light will flash if the preamplifier is drawing too much current, or if the cabling between the power inserter TO AMP port and the Preamp Output/Power port has a short.

If you Experience a Flashing Green Light:

1. Disconnect the cable from the preamplifier Output/Power port, and if the green light on the power supply returns to solid green then the preamplifier has a problem.

2. If after step 1 the green light continues to flash, this could mean that the cable or any other component that is connected between the Power inserter and the Preamplifier, must have a short from the center conductor to the shield/ground.

NOTE: If your antenna already has a built-in preamplifier/amplifier that requires power over the coax cable, installing the CM-7777v3, CM-7778v3 or CM-7778HD preamplifier and its power inserter will block the voltage from getting to your antenna's built-in preamplifier and you'd likely get little or no signal to your system. This scenario can cause damage.

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