SMPS=Switching Mode Power Supply
Firstly, see that the wires inside Ur cabinet are not coming in the way of the processor fan.
A loose power supply plug at Ur PC end may also b the cause of Ur problem.
Every SMPS or a PSU comes with a rating.
For example,my SMPS has a 300Watt rating.
Which means that it won't be able to support the hardware which requires>300watts.
Btw, the SMPS comes along with Ur cabinet.
P4 1.6GHZ Willamette core 400MHZ FSB 256KB L2 cache
Intel 845WN Mobo
Nvidia Riva Tnt2 M64 G-card
40GB Seagate 5400rpm HDD
15 LG Studioworks563N
Creative Inspire2400 2.1 speakers
16x DVD ROM
52x Samsung CD Burner