[GTALUG] a quick question about power supplies?

[Karen Lewellen]

Hi wise souls of computing.
One of the creative problems going on with my recently built computer is 
that the fan in the power supply no longer works.  Nor can I use the power 
button to actually turn off the machine anymore.
When it gets too warm in fact, I must flip the switch on the supply in the 
back..its scary, but so is overheating.

While I am still hunting for sighted help to fix the mess my prior contact 
left behind..the cd rom is disconnected too, I want to plan properly for 
the power supply replacement.
I have several, including at least one still in the box.
I am quite sure that the power supply capacity is too low for the several 
things the machine is doing, I have three hard drives in the unit, several 
internal boards in use those kinds of things.
Is there a guide, or rule of fun, for  determine how much power capacity 
a supply should provide based on how much work the computer processor will 
be doing?
  With appreciation.
Karen