Yes, that is essentially what I thought was the problem so I bought banana plugs for all my wires and i double checked that they're all snug and no fray wires are shorting anything out. Do you guys know if Pioneer will fix this problem? And if so, is it worth it?
You have eliminated one variable, but you have not told us what speakers you are using. The receiver is rated to drive 8 ohms. However most speakers are actually four ohms, no matter what the loudspeaker manufacturer claims the "nominal" speaker impedance is.
I have done some sleuthing on the net. As you state this is a prevalent problem with those receivers, that Pioneer has what they call a "Hybrid" amplifier circuit. In fact some consumers in their reviews call these receivers "junk" in their postings.
It seems to me the power stage must start to fail in these units sending them into protection. This problem seems confined to the front three channels, that are providing most of the power.
Now I can't get a circuit of the output stage, but you never can for that sort of equipment, however I have found reliable information about its modus operandi.
Basically it falls into the category of disguising junk and calling it an advance.
Here is the deal. There is a heat sensing transistor on the heat sink, that varies the bias of the output transistors as they heat.
To understand why, this is the deal. If the power stage is biased to class A, then there is a large current flow through the power transistors independent of output power. If you bias it class B then you have a lower dissipation in the transistor that closely tracks output power, but non linear distortion is high, especially obnoxious crossover distortion. So for practical purposes most amps are biased class AB.
So it seems to me that to market these receivers at the ridiculously low price they sell for, the power output stage is inadequate. This has been disguised by a temperature sensing circuit which swings the output transistor bias towards class B as the heat sink temperature rises.
The problem, is though that their slight of hand is likely inadequate for a lot of loudspeaker loads. Loudspeaker loads are all over the map, and more often than not very complex.
If that receiver has pre-outs, then I would buy a three channel power amp for your front speakers to bypass the receivers front set of power amps. If the receiver does not have pre-outs, I would send it to the recycling center. This seems a frequent enough problem, that I would not advise spending money on repair.
If you look for a replacement, I would set you budget much higher, or make sure you have a receiver with pre outs and purchase power amps for the front three speakers.
