Problems with Onkyo receivers can include the device not turning on, no sound, low volume levels, and problems with settings. Onkyo has been around since the 1940s and originally sold turntable pickups.
Onkyo was, in fact, the first audio equipment maker to supply receivers that could handle video and audio in HD.I believe Onkyo is really aggressive with shutting the relays off if a digital audio signal is lost, so it could be whatever you're noticing is a result of a blip in the audio stream. I vaguely recall setting someone's Onkyo receiver up back in the day with optical audio and they noticed the relays would click on/off when they changed channels - this long predated HDMI stuff.
Onkyo TX-SR602 receiver parts - manufacturer-approved parts for a proper fit every time! We also have installation guides, diagrams and manuals to help you along the way!.When in Pure-Mode, the device’s screen is shut off you will only see a blueish LED to indicate that the receiver is in ‘Pure-Mode’. The luminance can be changed, and also the blue illumination on the volume knob can be turned off. The screen on the front of the receiver gives a nice amount of information.Googling "onkyo blinking standby light" suggests the problem is, as dfergie offered, a short in the speaker system or cabling. A blinking light sounds like a fairly major fault. Offering a model number is always a better idea than a general category.
Onkyo has made dozens of 7.1 receivers.