Desktop

didn't connect anything that would draw excessive power you'd be okay...

I would probably just connect the motherboard & maybe the hard drive....I wouldn't connect any extra hard drives or CD/DVD drives....just the min. needed to power it up.

Mainly because you list yourself as being in the US and they do not have 240 V AC Power Distribution.

But in answer to your question provided that you are just testing and not using the full capabilities of the computer and running every drive you should be safe to test the computer.

What you will need however is the correct power plugs so if your M'Board uses a 24 Pin ATX Connector you Must have a 24 Pin Connector not a 20 pin connector and the Supplementary 12 V DC Connector Must be connected. So if your M'Board has a 4 Pin Supplementary Connector the Power Supply Must have one of these as well. The same applies if the M'Board has a 6 or 8 Pin Supplementary Connector the Power Supply Must have this connector as well.

Another thing with Power Supplies is that they are not all equal. Many of the cheap No Name Power Supplies are rated to Peek Loadings where as the better Name Brand Power Supplies are rated to a constant load. So in the case of a No Name PS rated to 400 W this is what it can supply for short periods of Peek Loads like that drawn when a computer is started. Where as a Name Brand Power Supply rated to a Constant Feed can have a lower stated Output Supply and still provide the same amount or required power.

For instance a Flower Brand 500 W PS doesn't supply as much Power for High Loads as a 350 W Antec True Power Power Supply does. So in that comparison the 350 W Antec is a better Power Supply than the 500 W Flower Brand.

Another big difference between the Name Brand Power Supplies is that they have separate Voltage Rails and Dual Feeds on the High Power Rails so instead of just 1 12 V converter they may have 2 or more with separate 12 V Rails inside the Power Supply with one Rail feeding the ATX Power Connector & Supplementary Plug and the other 12 V Rail supplying any attached HDD and so on.

The easy way to pick the difference between a Good and a usable Power Supply is to pick them up and compare the weight of the different units. The heaver units have more int hem and offer better over all Power Supplies Wattages for longer periods of time as well as better filtering of the output power so that it is closer to it's stated values in Voltages without variation.

Col