I have an idea what's going on. It sound like your PSU's getting weak or underpowered. When you removed some components it freed up the power that was feeding them. I can see why your fan sped up as it's getting more power to it.
Sounds about right?
EDIT: on second thought after what you said about the component almost on fire, in that case it's drawing too much power. Your PSU may be ok after all.