My Denon Receiver stop working when electric kept going on & off

Thist could be due to a short in the amplifier or in the power supply. You can try the following: disconnect all speakers and components. Then see if the unit powers up. If it does, turn it off, connect one item at a time until the unit fails to come on. That may identify the bad component.

However, it the unit never powers up when it is devoid of speakers and components, repair is going to be more tedious, possibly cost prohibitive. https://www.justanswer.com/home-theater-stereo/8uupb-hi-denon-avr-1312-receiver-just-stop-working-suddenly-check-chassi.html

https://support.denon.com/

If it is a modern receiver that is more computer than radio it is necessary, like all computers, to allow a complete boot before switching off.
A problem with the supply could have meant the equivalent of switching off, possibly several times, before booting is complete that could have upset the software.

Depending on the problem that caused the power to keep going off could have produced a voltage spike that is capable of damaging sensitive electronics.

Have you checked to make sure it didn't restart your entire system? If not you'll have to double check everything is connected correctly, turn everything on, and change the channel on the TV back to whatever Composite video or HDMI setting it was plugged into...then make sure the Denon receiver is set to Cable

Try a reset to factory defaults and reprogramming your preferences. Time consuming, but sometimes things go bung inside the microprocessor controllers.

Help with hooking PS3 to a Denon Receiver. It worked before, but I had to move everything to a different location and when I hooked it back up the PS3 has sound but no picture. I have it hooked directly to the receiver with and HDMI cable (the receiver is hooked up to our cable box which is directly hooked to the tv via HDMI cable).

You will have 2 choices here, replace it or have it repaied

perhaps u might consider going to a(n) (unauthorised) repair centre. just check with folks around u or maybe audio forums within your area. authorised agent doesn't always mean the best. i suspect they may have used reconditioned components.

When you indicate system stopped work, I assume you mean the receiver is dead or malfunctioning. I need more info for more advice

i just had the same thing happen to me what did you do to fix it?

please apply a new fresh battery to it-confirm from right orientation(polarity)-try to apply a contact cleaner spray over the bad button and press it many times.-remove any thing between remote and receiver.-you can use universal remote and confirm befor you buy the new remote that it support your receiver.