what's the problem: new psu or old mobo

[NilknarfLP]

A couple of days ago my computer started emitting unpleasant smells, and soon after smoke was pouring from the back of the power supply. Needless to say, I turned off the computer asap. Then I unplugged everything, tossed the old psu, and got an antec trio 430watt (my old psu was a zalman 480watt). When I installed the psu and flicked the switch, nothing happened. No lights, no fans spinning, nothing whatsoever. I rechecked everything and tried again but no dice. I know its more likely that the mobo got fried when the psu died rather than the new psu being faulty, but I'd like to get a couple answers before I RMA the mobo. First, is it a good sign that my computer shut down normally even while the psu was smoking? Second, is a psu's fan supposed to run when it's plugged into the wall and the switch is flicked (no other connections)? The new psu's fan doesn't. I don't think the new psu isn't capable of handling my computer's components because I'm only running a pentiumD processor, an 1800xt video card, and a single 80gb 7200rpm hd.

 

[Old Hippie]

Second, is a psu's fan supposed to run when it's plugged into the wall and the switch is flicked (no other connections)?

No.

First, is it a good sign that my computer shut down normally even while the psu was smoking?

I have no idea.

Most MBs have a light if the PSU is plugged in and turned on. No light = a really bad sign.
Good luck with that RMA.