Replaced CPU now system won't power up

[Sandan]

This is my daughters system...It is K7s5apro ECS board, 250 watt antec PSU, 750 megs pc2700 RAM, WD 120G hard drive, replaced amd athlon 1.4 G with amd Athlon xp 2200+. Pushed the power button and CPU fan spun for about half a second then nothing. Fan went off and nothing more happened no beep codes. I tried to put the old Athlon 1.4 G back in and now it won't work either (same symptoms). I also replaced the fan heatsink with one that is made to support the XP. I tried to change the PSU by unplugging the main power and plugging in another PSU (Although I didn't connect up hard drive to that PSU)...But same issue fan on for half a sec and nothing more. Any thoughts?

 

[Puffnstuff]

Are you plugging the cpu fan into the correct header on the mb?

 

[Sdiver2489]

I have had this happen sometimes seemingly randomly...try plugging it into a different outlet.

 

[sniperruff]

power button on PSU turned on?

 

[0roo0roo]

reset bios with jumper.

 

[RallyMaster]

use CMOS reset jumper. Put that 1.4GHz chip back in. if that still doesn't work, try changing the PSU. after that, if it still doesn't work, you might have pwnd the mobo.

 

[jkresh]

Reset the cmos, also if that doesnt work try reseting it with it unplugged from the wall and the cmos battery removed (leave it out for about 10 minutes).

 

[Sandan]

Ouch...Thanks for the input, I did everything recommended and all I can think of...Changed PSU, Put old CPU back in, Swapped out the RAM, reset cmos, took cmos battery out for 10 min, even changed cmos battery, tried another plug outlet, tried to do a live jump with screw driver where power switch connects to rule out bad power button, switched out fan heatsink, cpu fan is on correct fan connect, and yes the psu power button is turned on...I must have fried the MB. Don't know how that happened because I can't see any burnt transistors..There was no light smoke or smell...Checked to make sure no metal interference with MB to short it out. First time a MB died without any traceable cause. The only little quirk is when I put the new cpu in the socket A, it was hard to get it in and had to work with it till it snapped in. I don't think that hurt anything...no cpu pins bent.

 

[Nathelion]

I had a similar problem when working on a notebook
i took everything apart, including taking the CPU out, then put it back together again. When I then tried to boot, the fan would spin for half a second, and then nothing. Exactly your symptoms.
What had happened was that I hadn't managed to seat the processor properly. Do you have one of those sockets where you put the processor in and then you have to slide it over a ways to lock it? My socket was real uncooperative and took a ridiculous amount of force to make it snap back into place and lock. You have to make sure it really goes all the way over (without breaking anythihg...). At least in my case, the edge of the CPU board lined up with the edge of the socket when I had gotten it over all the way. Try to determine if it's actually seated correctly, it might be you're having the same problem.

 

[Sandan]

Thanks Nathelion, I seated the processor correctly. I noticed that the cpu has a hairline crack running across the die. I put the old cpu back in and this time it worked. I bought the xp 2200+ through ebay at a place called assured auctions. I emailed them to see if they can send another.