AT style Power Supply - simple question - how to cable to power switch

[lotto]

I need to replace the power supply in my system, which has an AT-style tower.&nbsp;&nbsp;The original PS and the new PS both have four single-wire cables going to spade connectors at the power switch on the front of the tower.&nbsp;&nbsp;These cables are not color coded the same in the two PS units.&nbsp;&nbsp;The original has a black, a white, a brown, and a blue cable.&nbsp;&nbsp;The new one has two blacks and two whites.&nbsp;&nbsp;Being very cautious, I want to know how to connect these four cables correctly.&nbsp;&nbsp;No instructions came with the new PS.<br><br>Viewing the switch's spade connectors from inside the case, the original connections were: upper left = black; upper right = white; lower left = brown; lower right = blue.<br><br>My best guess is to plug one black and one white onto the connectors that had black and white, respectively, and then to connect the remaining black and white plugs arbitrarily to the remaining connectors, but I could imagine scenarios where that might get me into trouble.

 

[BenLett]

I have found that Black is always black Red is always red but white can be any other color except green.&nbsp;&nbsp;

 

[clivo]

Normally, brown and black switch the live line, with brown being the AC source. Blue and white switch the neutral line, with blue being the AC source.
In your case black switches live and white neutral. As both poles are switched there is no safety issue involved.

 

[lotto]

Thanks, guys. Problem solved. The vital information I needed was that the switch interrupts, or closes, simultaneously, the hot line AND the neutral line. With a couple of continuity tests at the switch and the power cord, I hooked it up with confidence and all was well.