My Onkyo NR-905 Receiver is making my speakers chirping.

Hi Everyone,
I did more research and find out on other forum that Onkyo is known for overheating.  I installed a temporarely fan behind the Onkyo yesterday and that solved the problem. That cooled of the Onkyo and no more chirps.  I have the latest firmware which is 1.08, so it is not the firmware.    These units get so hot that I can even keep my hand on the top of unit for more than 30 seconds.  Gets very hot.   Some have put internal fan in units.  I will just get a fan and adjust the fan to push air from the back and top of the unit.  I Thank You very much for all your feedback.  Much appreciated.

I agree with sfall. You need to determine if you are having the problem with both digital sources and analog. If you tune to FM radio, do you still get the chirp? How about a CD player using the analog L&R RCA inputs? Do you hear the chirp on all inputs, or just one?

What are your digital sources and how is the signal routed (transport to dac)? Does the noise happen with just digital sources, or analog as well? If you're not sure, get a cd/dvd player that has analog rca outs, and plug it into an analog input on your receiver. Let it play for a while and see if it still churps. Also make sure haven't connected any of your sources to a phono input by mistake.

To me, it looks like you have either a digital transmission, or some type of gain related issue. Since you don't know exactly where the problem lies, you need to rule out as much as you can, and force the issue to reveal itself by elimination.

The speakers I am running with my Onkyo receiver are Definitive Technology brand.  I already change the guts in one and it is making it again. I believe  it is not the speakers.  Maybe it needs to be updated with the latest firmware?  

Speaker caps either gone or failing (at a minimum) and/or blown driver ???

some experiences links: 


http://www.head-fi.org/t/415732/annoying-chirping-sound-from-speakers


http://www.audiocircle.com/index.php?topic=94615.0

http://ask.metafilter.com/150834/Why-is-my-laptops-AC-adapter-chirping


http://forum.polkaudio.com/discussion/109373/chirping-speakers


http://www.clublexus.com/forums/ls-4th-gen-2007-2017/489062-no-audio-speakers-are-chirping-wtf.html


http://www.justanswer.com/electronics/47pxt-tx-sr705-makes-clicking-chirping-sound-mostly-right-fron...

Never heard of electronics suddenly creating a speaker  "chirping" sound phenomenon. ONKYO has a well-known and well-travelled lengthy legendary poor track record of HDMI board failures, but that is USUALLY a catastrophic failure in nature and easy diagnosis , and not a "chirping " in your speakers.

Q: Have you first considered and ruled out that your speakers are the culprits (sudden power surge fried them, caps gone, high listening volume and sudden amp headroom limits exceeded created a transient clipping that fried them , ???)

I would rule that out first before I journeyed down a slippery slope of receiver expensive diagnostic and repair services, the cost of which will likely greatly exceed the unit's FMV. In that case, probably not worth it to fix.