Help CPU or PSU or Mobo is dead

[GFKiraR]

alright well here is my current problem. Thursday i get and install my new ATI 4850 X2, everything works fine (upgrading from a 8800GTS), although Sapphire says i should have at least a 650Wt or higher PSU.....my current one is a 600Wt( i know but i still wanted to see if it would work an it did. alright so everything worked fine with it, i was able to play Crysis an tested it with 3DM06 and everything was fine. Friday i get my Phenom 9600BE an put it in again everything works but i notice significant FPS drop in Crysis, before with my old Athalon X2 5000+ BE oced-2.9Ghz, FPS and gameplay was fluid and never slowed to a point where there was any noticeable gameplay lag. alright so then i decided that it would be best to switch back to my Athalon until i got a new PSU which would allow me to OC my CPU and have sufficient power for the video card. So i go ahead and switch them.(yes i did properly discharge and kept so during the CPU transfers). Alright so i did that an when i turned back on my system it powered up, Lights and fans are all on But it is not posting anything on screen. I have tried booting it up with my old 8800 1 stick of ram an HD only, no other drives or fans being powered. i have tried removing the battery from the motherboard while it is totally un-plugged, nothing , I have removed the PSU an tried it on my backup system and it powers that up no problem. So could it still be my PSU because ive heard of them powering on but not letting the system work but it lets this backup work so i dont know what to think about that now. otherwise i think it could be my CPU but they both worked before an i know i did everything properly still im not sure. could it be my motherboard but it it is how? so that is my current problem an i dont want to go spending alot of money an something i dont need to get by with.
right now im leaning towards the Mother Board being the problem


Current config of down system
AMD Athalon X2 5000+ BE(will put the Phenom X4 9600BE once i get new PSU)
ASUS M3A Mobo
4GB Gskill 1066 Ram
Sapphire 4850X2 2Gb.
Coolmax 600Wt PSU

 

[GFKiraR]

alright so while tinkering with it i have come across possibly more issues that point to the Motherboard.
When i turn on the system the light at the front of the case does not indicate any HDD activity at all and there is no light coming from the ethernet port that usually is there. and second normally when i turn on the system lights on my Keyboard normaly will light up indicating that it is receiving power from the computer but it is not at all right now. i know its not the video card because it has an L.E.D. on the back that glows red when there is improper power connection and Green when everything is ok.
i have tried removing the Cmos Battery while the system is dissconected and hitting the power button to discharge any possibly stored power. one thing that baffles me though is the fact that both the CPU fan and the Rear case fan that is powered by the mobo both come on along with a light on it that indicates it is receiving power. still no idea what it the problem

 

[misry]

Do you get a beep code?

1 beep all is kosher. No beep is CPU, memory or M/B. I think you might have mentioned a series of beeps but if you don't have a PC speaker attached at this time and later get one you need to look up the code for your particular M/B. Remember to listen for a pattern, i.e. 1 long 2 short, a 2 second pause and it repeats.

 

[GFKiraR]

Ah no Beeps at all, and yes the speaker is connected. another thing i just tried on it was to try booting it with only 1 of my 4 sticks of ram and all peripherals(Hdd included) disconnected except for my video card and still nothing

 

[misry]

Reseat the video and if that doesn't work we're looking harder and harder at the MB.

 

[main_man_vern]

Remove all devices except the CPU and PSU. Start the machine and you should get a post error code (several beeps). This will at least tell you that the MB is working correctly by posting the beep codes. If this test fails I would have to think you have a bad MB... (well at shot BIOS at least).

 

[GFKiraR]

Yeah i totally pulled the system apart an cleaned and reseated everything but nothing worked, my new motherboard came in and everything works just fine, so im at a loss but i guess there was some sort of hairline crack or something that caused the issue, anyways it really doesnt matter now i guess since ive got a new motherboard. still kinda wish i could figure out what the problem was

 

[misry]

You are at the cost effective point. You've found the problem and fixed it. If this were a customer machine you would hand them the bill and move on to the next one. Because of the complexity of a modern MB and probable lack of component level tools, i.e. EEPROM programers, O-scope, etc., it could take you weeks to find a parted trace in the MB or a shorted pin somewhere. If you've got the time and patience, great, but don't keep paying customers waiting while you do it.