Antec TPII-480 boots pentium D dual core but not AMD Athlon 7750

[ORiON_697]

I recently aquired an old intel pentium D dual core system with the intent on building a basic HTPC. The power supply in this is 480 watt antec TPII-480.

my current system consists:

AMD Athlon 7750
Gigabyte M61pme-s2p
3gb ram
ECS GT240
2x Seagate Baracuda 160gb
Thermaltake XP550 NP (430 watts)

i decided to swap the power supplies as the antec psu has a higher wattage and the thermaltake psu is much quiter and would suit a HTPC better. after about an hour of attempting some sort of cable management i put my case back together, plugged in my bits, turned on the AC and hit the power button. nothing. i turned the ac off and on and tried again. the cpu fan twitched then.....nothing. i just don't understand. the Antec psu powers the intel pentium system absolutely fine and so does the Thermaltake. but the Antec will not power up my AMD main system at all. i'm completely lost and have spent the last four hours googling and swearing and hoping someone can tell what the hell is going on! Please help!!

 

[mosox]

http://www.tomshardware.co.uk/forum/261145-13-perform-steps-posting-boot-video-problems

 

[ORiON_697]

i appreciate this but the power supply is working. however it only works with the intel system. it won't even turn on at all in the amd system. i have checked all plugs and cables numerous times and the amd system is functioning but only using the thermaltake power supply

 

[megamanx00]

It could be that something is wrong with the 4-pin CPU connector or the 20pin connector on the Antec PSU. That Pentium D board may simply be more forgiving in that regard.

 

[iam2thecrowe]

the older antec psu's had some issues with bad quality capacitors. It may not be supplying enough juice anymore and the athlon tips it over the power requirements.

 

[ORiON_697]

thanks guys. yeah i had pretty much come to that conclusion at about 4 in the morning after another 6 hours of Google searches. Looks like I'm up for a new psu. Sweet. :|