If you lost all channels when th ePA18 was installed, then either the PA18 has an error in the cabling or it's defective. It's fairly easy to check the most common things.
1) Unplugging the power supply is NOT a valid test. This turns the amp into a 30 dB attenuator which will allow only the strongest signals to get through. You must *completely* remove both the amp and the power inserter to avoid this condition.
2) Verify that there are no devices in the coaxial cable run between the inserter and the amplifier module. A splitter with a single DC pass port may be used, but it is necessary to verify that the proper cable goes on the proper output port. An example is shown here:
http://www.antennasdirect.com/cmss_f...itter_Opt2.pdf
3) If there are no apparent cabling problems and there are no splitters in the line, connect the amp per instructions and plug in the power supply. Within 30 minutes, a normally operating transformer will feel slightly warm to the touch. if it remains at room temperature, either the receptacle is unpowered or the transformer is open. If you have a multimeter, the transformer primary should measure between 350 and 400 ohms. If it reads open-circuit, the transformer has failed and will require replacement.
4) If you have a multi-meter, you can check for power at the amplifier end of the coaxial cable. With the transformer plugged in, you would normally see 16-18 volts DC at the cable end at the amp measured from the center conductor to the shield. Take precautions so that you do not accidentally short the center lead to the shield. If you do, you'll likely blow the primary of the power transformer.
5) If everything else checks out, the amp is likely dead. Contact us through normal channels for warranty assistance.