[VIA] MSI-7021 (KT6V-LSR) and Sempron 2500 problem.

Question

I bought a AMD Sempron 2500 1.75ghz and a MSI-7021 KTV6-LSR, I connected the Sempron to the motherboard and powered up, well I got power to the fans, but no activity and no sounds. I plugged in the LED diagnostic kit that came with the motherboard and all 4 red lights are on, according to the manual this means either a fault with the CPU or it aint seated properly. So I reset the CPU and the same 4 red LED's came on again.  I thought it could be a PSU supply problem, so I disconnected all the hard drives and the DVD-ROM drives and still the same problem occured.  So I decided to test my old Athlon 1.2gig CPU in the motherboard and the same problem occured again, no activity and all 4 red LEDS on the diagnostic.  I also disconnected the 2 DDR memory chips.
I dont have one of those 4 pin power connectors, do I need on of these.
I tested the new Sempron in my old PC motherboard, an ASUS A7V-E and it powered up without any problems, so obviously it cannot be the new Sempron CPU that is fauly.
Can someone point me in the right direction.  I hope I have supplied enough information.
Here is my full system spec
Antec 300W  PSU PP-303X ATX 2.01, +3.3=14A, +5=30A, +12=10A
AMD Sempron 2500 1.75ghz with supplied fan and heatsink
MSI-7021(KT6V-LSR) motherboard
ATI Radeon 9800 Pro 128mb
2 x 512mb Crucial DDR PC3200 • CL=3 • UNBUFFERED • NON-ECC • DDR400 • 2.6V • 64Meg x 64
120gig Hitachi UDMA100
40gig Maxtor UDMA100
Pioneer DVD-120 DVD-ROM Drive
Pionner DVR-104 DVD Writer
Creative Soundblaster 5.1 PCI Soundcard
Windows XP Pro SP2

Answer 1

Quote
I would need the 4 pin even for a old Athlon Socket A CPU too.  Why is this exactly, does the KTV6 use more watts than a normal older mobo.
You need the 4-pin because it is part of the mainboard's design power.  That 4-pin connector exclusively supplies your processor.  No 4-pin lead = no power to the processor.
And you are better off with the Antec than the Tagan.  Tom's Hardware, based in Germany where Tagan is prevalent, has had nothing but failures from Tagan power supplies.  Most recently THG chose a Tagan for their Intel and AMD Stress Test - the Tagan died.  To be fair, the Tagan was a pre-production test unit, but the authors did make a point of saying this was not the first Tagan that has died in their lab.