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Denon Receiver Turns Off and Blinks Red Quick Fixes

Denon Receiver Turns Off and Blinks Red Quick Fixes
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Denon receivers are excellent devices for improving your home entertainment experience. However, even modern Denon receivers may develop a problem where it turns off and blinks red. Keep reading for the details about what this means and how to fix it.

The Denon receiver red light is known as the Protection Mode Light. The light comes on when current or heat sensors detect unusual conditions that can harm the device. Sometimes, this light just indicates that the device is restarting to attempt to resolve the issue. 

Let’s get into more detail about what the Denon protection mode is and how to fix it

Why Does My Denon Receiver Blink Red?

If your Denon receiver turns off and then blinks red, it shows that it is in “protect” mode. In other words, your receiver has detected a problem and shuts down to prevent further damage.

It blinks red to advise you to fix the issue as fast as possible before attempting to reuse it. This can happen if there is a current surge or if the device is overheating.

For example, the Denon 4306 often shuts off at high volume if it is being driven too hard and overheating or there is an overcurrent issue. 

How Do You Fix a Blinking Red Light on a Denon Receiver?

If you want to fix your Denon receiver that keeps turning off and blinking red, we recommend that you do the following:

1. Increase Ventilation

Consider increasing ventilation since it’s one of the most common culprits. It’s easy to fix. Follow the steps below to achieve your goal.denon receiver overheating

  1. Remove physical objects near the receiver (Ensure the room is spacious enough)
  2. Give a few minutes of cooling time (Wait for the protection light to go out)
  3. Try powering on the receiver

You can use an AV receiver cooling fan like the AC Infinity AIRCOM S6, Quiet Cooling Fan or a laptop cooler like shown in the image above to help you cool the device faster. A good choice for this purpose is the TeckNet Laptop Cooling Pad, 6-Fan Notebook Laptop Cooler Cooling Pad with LED Lights, Dual 2.0 USB Ports, Suitable for 12-19 Inch Laptops.

Note: The circuitry will reset automatically during the cooling time. Once everything is fine, the protection light will go out.

2. Check Your Speaker Connections

When your connections don’t allow the seamless transmission of electric signals or current, your Denon receiver will experience this problem. It would help if you did the following to fix it:

  1. Turn off the receiver
  2. Check all the wire connections
  3. Ensure the wires are firmly connected
  4. Turn on the speaker
  5. If the protection light goes on immediately, disconnect your speaker wires at the side of the receiver
  6. Reconnect the speaker wires one by one to try to detect the faulty one and replace it
  7. Ensure all the speaker connectors are set up correctly and not damaged. 

3. Fix any Impedance Issues

If you use the above step and the protection light goes on after a while or when you increase the volume, your speaker impedance could be lower than required.4 ohm speakers and receiver

Confirm whether this is the case by reading the ohm values indicated on the receiver and the speakers.

Remember that if the speaker resistance is too low, it will pull too much current from the receiver. In this case, the receiver might go off almost immediately. For example, if you use a 4 ohm speaker with your receiver, you should keep the volume low or the receiver will go into protect mode and you will risk damaging it. There are however some receivers that support 4 ohm receivers

What should I do if lower speaker impedance is the issue? You have two options. These are:

  1. Match the impedance: This involves buying modern speakers that match your Denon receiver. Check the manual, but in most cases, 8 ohm speakers are a good choice. If you don’t want to spend on this for any reason, you can opt for the following method.
  2. Use Series Connection:  Series connection allows you to increase your speaker impedance quickly by using multiple speakers. The impedance will be equal the sum of the resistors since you are connecting your speakers end-to-end.

Note: Choosing a parallel connection won’t help you in this case since it reduces speaker impedance. To get the speaker impedance, you multiply the value of your resistors and then divide the result by the sum of their value. Since this connection reduces the speaker impedance, it could worsen the situation.

4. Reset the Receiver/Initialize the Microprocessor

If none of the above steps seem to work for you, initialize your receiver’s microprocessor. In simple language, reset the receiver.

The process is simple, and you’ll hardly require more than a minute, though it’s highly effective. Once you are done, your receiver could be as good as new.

Check the owner’s manual for the correct procedure for your Denon receiver model.

Note: Reset your Denon receiver as a matter of last resort. This process will delete all the setup configurations, meaning you’ll need to set up your system again once you’re done.

5. Call an Authorized Repair Expert

If you have done everything within your means and everything fails, or you can’t reset the receiver yourself, you should take the machine to an authorized repair center.

They’ll use advanced tools to diagnose the nature of repairs that the device requires.

Remember that you’ll need an authorized Denon repair expert if you have a reason to believe that the device has malfunctioned.

In some cases, as you troubleshoot, you may discover that you have electrical issues. Maybe the power outlet has some defects. In this case, call and certified and experienced electrician instead.

Why Does My Denon Receiver Keep Turning Off?

Let’s say you allow the receiver to sit for a while but when you turn it on, it keeps turning off. Your Denon receiver could be turning off and blinking red due to the following reasons:

Hardware Issues

Hardware or physical problems can cause your Denon receiver to keep turning off and blinking red. A short or bad speaker will likely cause this. Generally, any problem with your connections can cause this issue.

Software Bugs

Some Software-related bugs in the microprocessor can also give the wrong signals and trigger the device to turn off and blink red. Some of these problems can clear away on their own after a short while. In some cases, if you power on the device again, it can work perfectly.

If this issue starts occurring after a firmware update, check out our guide on how to update your Denon receiver firmware and how to fix firmware update issues.

Lack of Ventilation

Lack of proper ventilation is another common reason your Denon can turn off and then blink red. The circuitry typically produces a lot of heat.

However, it cannot operate as required in a hot environment. So, whenever your receiver overheats, it shuts off to prevent your audio system from blowing off or malfunctioning.

Low-Speaker Impedance

Low speaker impedance is a common cause of this issue that many laypeople often ignore since they don’t know the consequences.

If your speaker or speakers have a lower impedance, it means the speaker requires more power than the receiver you’re using can supply. The impedance mismatch can cause the receiver to overheat and destroy your speakers and other essential devices.

If you are using a lower-impedance speaker at a low volume, you may not experience this. Remember, the amount of current that speakers require often increase as the volume increase.

Overall, if your receiver keeps turning off, you should consider whether overheating due to impedance mismatch and lack of adequate ventilation as the main culprits. Of course, this only applies if you don’t have a reason to believe otherwise.

How Do You Reset A Denon Receiver? 

If you’ve used all the tips we’ve shared here to fix your Denon speaker without success, you can reset it. This is the perfect way to reboot the receiver’s microprocessor to restore its normal operations. You should consult your user’s manual to find the ideal steps to follow.

To reset your AVR-S510BT Denon receiver, ensure the receiver’s power is turned off. After that, long-press the “SOUND MODE,” the “TUNER PRESET CH+,” and “POWER” buttons simultaneously until the display starts flashing at approximately one-second intervals.


Modern Denon speakers are designed to turn off and blink red whenever they detect any issue that can cause further damage. Once you understand the problems, you won’t be stressed if your Denon receiver begins to behave this way. In this article, we’ve covered all the essentials you need to help you explore the underlying causes of the trouble and how to fix it.