I have owned a Denon AVR-X3000 for about four years. Yesterday evening the centre channel seems to have gone defect. Some observations: The noise comes only from the centre speaker. The noise sounds like fire crackers and is sharper than FM noise (a 'crackle'). Not using the speaker -stereo mode- or disabling it in the speaker config disabled will remove the noise. The volume of the noise is affected by the AVR volume level. The centre speaker still plays sound. The noise is 'in addition' (hard to tell as it is much louder). It is regardless of 'Audyssey' being turned on or not. When listening (analog) CD input, there is little noise at the start, increasing in frequency as the AVR is used. It seems related to temperature. The noise also becomes more when there is not music input, e.g. CD on pause. When listening to Spotify, it is continuous noise, no matter if I just turned it on. When getting HDMI input, it is silent when there is no sound, sound, including menu-tones will be very distorted. I reset the receiver and did the Audyssey setup. Instead of the ploing tones from centre speaker, I got noisy ones. It didn't change anything. There seems to be perhaps a bit more 'random'/undefined behaviour in addition to the above; there is probably more that I haven't pinned down yet. As I would like to use the Denon -incl the centre channel- for some more time, the following question: Is a schematic available for this device or does anyone have a suspicious which component should be replaced for this? Does anyone recognize these symptoms and know if it is hopeless or not?