Denon AVR-988 IR Codes

To reset the AVR-988 to factory settings, turn off the unit. Then, while holding the "Speaker A" and "Speaker B" buttons, press the "Power" button. Keep holding the buttons until the display starts flashing. This indicates the reset is complete.
Check that all connections are secure. Ensure the correct input source is selected and the volume is turned up. Also, verify that the mute function is not activated. If issues persist, try performing a factory reset.
The AVR-988 does not support firmware updates via the internet. For updates, contact Denon support or visit an authorized service center for assistance.
Connect the speakers to the corresponding terminals on the back of the receiver. In the setup menu, select 'Speaker Setup', then choose 'Speaker Configuration' to set the system to 5.1. Adjust the speaker size and crossover settings as needed.
Regularly dust the unit with a soft, dry cloth. Avoid using chemicals or water. Ensure that vents are free from obstructions and clean the remote control with a slightly damp cloth if necessary.
Ensure that the receiver is placed in a well-ventilated area and that vents are not blocked. Check for high speaker impedance or short circuits in wiring. Consider using an external cooling fan if overheating persists.
The AVR-988 does not have built-in Wi-Fi or Bluetooth capabilities for direct control via a smartphone app. Consider using a universal remote app that supports IR blasters if your phone has this feature.
The AVR-988 does not have built-in Bluetooth. To connect a Bluetooth device, use a Bluetooth audio adapter connected to one of the available audio inputs on the receiver.
Connect the included calibration microphone to the front panel. Navigate to the setup menu and select 'Auto Setup'. Follow the on-screen instructions to measure and calibrate the speaker levels and distances.
Ensure HDMI cables are securely connected and check for cable quality and compatibility. Try connecting to a different HDMI input on the receiver. If issues persist, update the firmware on connected devices and reset the AVR-988.