Home Button Constantly Pressed Without Touching Device
So... I have an iPhone 5 with a home button problem. I pre-ordered this when the iPhone 5 was released, so it's out of warranty by now.
The problems started happening around September and I sent it in for warranty repair in October. The device worked well for about a month or so, then toward the end of November it started doing the exact same thing. Now it's December, and I'm using a back-up iPhone 4 until I either figure this out or scrap the device for parts and wait for whatever 2014 brings us for iPhones..
I can leave it sitting on the table and Siri will randomly activate. I can also try pressing the home button and it will do nothing or register a triple-press. When I hit the power button on top of the device, it will randomly take screenshots.
The behavior is leading me to think that it is constantly registering my home button as being held down for some reason.
My first approach to the situation was to address the mechanical function and replace the home button and the home button cable. After replacing those parts, my iPhone 5 is still misbehaving.
Is there anything else which could be a mechanical factor contributing to this behavior or is there anything software-related which I could also attempt?
I've already attempted a factory restore, and it's running current iOS 7.0.4...