"First make sure the wattage and impedance (ohms) of the speakers are compatible with the receiver and then follow these steps.
1) Power receiver off and disconnect from the wall
2) Disconnect all speaker wires; you may find it helpful to label the wires for ease of reconnecting them
3) Plug receiver back into the wall and power the unit on, you will see the NG: LCRSLSRBLBR message again
4) When the NG message pops up, please press and hold the ENTER button (located on the right side of the receiver front), while holding the ENTER button down, with your other hand, press the power button. Your unit should either shut off or go into the AMP DIAGNOSTIC mode. If the unit shuts off, turn the unit back on, you should see AMP DIAG on the front, let the unit run through the process
5) When the diagnostic is finished you will have one of two results, either the NG message will reappear or you will get a message of CHK SPKR WIRE, if you get the CHK SPEAKER WIRE please proceed to step 7
6) If the NG message reappears, please power the unit off as it will have to go to service. Please use this link to locate your closest service center:
Please get the unit to them with a written description of what has happened to the unit along with a copy of your bill of sale. If you will have to ship the unit, please call the service center prior to shipping the unit to alert them that the unit is on the way.
7) If you got a CHK SPKR WIRE message, please check all speaker wires, speaker and the speaker volume controls for frayed wires, kinks, or other potential issues that may have cause a short circuit. Next perform a factory reset on the unit by pressing and holding down the CBL/SAT button on the front of the unit, while holding this button down, press the “POWER” button. You should see CLEAR on the front of the receiver. You will have to go through the initial set up again.
8) If you found no issues with the speaker wires or speakers, please reconnect the speaker’s one pair at a time and power the unit on upon each connection, test the output to see if the NG message re-occurs. Repeat until all speakers are connected."