While watching TV or even when all components (except the Denon receiver) I hear random noises through speakers. What could be causing this?

Check your receiver. It should also have a single composite video output jack as well. Usually one of the component video inputs on the tv is also labeled for composite use as well.

Typically, Zone 2 is for a different program than the one you're hearing in the main listening room. You can choose any source for Zone 2 EXCEPT a digital one.

The clicking noise is the protection circuit that is kicking in and repeatedly shutting off the unit because an internal fault has been detected.
If the problem happened before a power surge, and the power supply looks damaged, then the PSU must be replaced.

If the unit is only 3 months old, better contacting Denon and having the one year factory warranty validated, rather than DIY.

See : Denon USA | WARRANTY or contact Denon for more info on your limitede warranty cover.
If the unit has been taken apart, this may invalidate warranty.

If you want to DIY you can find parts here, or from Denon.

Do not forget to leave feedback.

Thanks.

HDMI is a High Definition Multimedia Interface and has the capability to transmit both AUDIO and VIDEO all in one cable. Your setup right now is transmitting 2 audio frequecys (L/R stereo RCA and HDMI) into the Denon inputs. Not necessary! I would recommend eliminating the red/white audio cable from the direct tv box to the Denon.

After doing such, your receiver should be able to process audio/video signals appropriately. REMEMBER to unplug all POWER CORDS before reconnecting any speaker/audio/video cable, as it may cause a small electrical surge and fry a micro component in your system!

no the problem is at the plasma you will have to change the setting back to the scale range that will accept the signals from the Denon, see Plasma's manual for instructions

It cant up-convert component to hdmi. Input and output has to be the same. However, you wont lose anything cuz hdmi and component are comparable

Yes I believe you have a hardware failure in your audio amp IC. In some cases, a speaker will cause all the audio to distort, but its very rare for a speaker to cause this issue. If you just got it, you can return for a quick resolution, or contact a local repair center for a new main board replacement.

Same issue with my AVR-589...2-15 minutes after sound is playing (via TV or DVD). I checked all wires and speakers. Even reconfigured to audio only (analog) coming in, same issue. Put my old Denon receiver in and the problem disappears...possible overheating issue with this new unit?

i had this condition on another denon a/v receiver it started clicking got worse as time went on progressed to snaping sound more so when switching modes ie dvd to tv etc then l/frt speaker would cut out found by gently tapping l/side of the chassis it would pop & snap sent it out to denon & they replaced the dsp unit no problem since hope this helps Alan

The noise is in the pre-amp stages of the Denon AVR. It might be caused by bad capacitors.