Computer shuts down very quickly.

I recently upgraded a computer from pentium 3 550mhz to a amd athlon 64 3000+, a asus a8v motherboard and I also added a 400w power supply from Sparkling Power which is a chinese company(my dad got it so don't ask me about them). The computer was infected with viruses and other stuff before and was very slow. I first started up the computer before cleaning it and I got the blue screen of death so I decided to nuke the hard drive that had the OS on it. So I did and all went fine. I started it up but I forgot to put the power cord back in the hard drive so it didn't detect it. It started up all fine except no OS which was what i was expecting. Then I plugged the power back into the hard drives and then I put everything back together. I pressed the power button, the lights lit up but like almost instantly after the computer shuts down and nothing appears on the screen. I'm thinking its the power supply but its 400w so I don't know what is going on. Any suggestions?

 

This is pretty common. Since you changed the CPU and motherboard (or so you said), you might have applied the thermal paste or thermal pad on your CPU incorrectly. As the electricity flows to the processor on power-up, the processor heats up quickly. Poor application of TIM (official name for thermal paste) will not allow it to dissipate correctly, and your computer will shut down after only a few seconds. Try re-applying the gel or pad, whatever you have on it.

 

Since you have an AMD 64 3000+ yourself you should know that the thermal paste is already applied to the heatsink by the manufacturer therefore making putting the thermal paste on idiot proof and I do happen to have a computer that produces more heat that has very little thermal paste because i accidently had some of it rubbed off while doing maintenance and it has not caused my computer to ever do that. And thermal paste doesn't not effect the cpu temperature significantly enough to make it over heat unless it has been overclocked and still cpus don't heat up fast enough to make it shutdown within a second of starting up. Thanks for trying but you next time get your info right.

 

I merely offered advice and you insult me? That information is correct for the most part; it is a common problem for first-time builders. I myself had that problem when I was new in the trade. "Thermal paste doesn't affect CPU temp enough to make it overheat"? I've watched non-overclocked CPUs melt like ice cubes because of a lack of TIM.
Anyway, I'm gonna run the moral high ground and keep trying. Your next most likely problem is one of power; indeed, you should check your power supply to see if it is running (swap it out with another system) correctly. Make sure that there are no shorts on your mobo or with other components (such as a screw caught between your mobo and case, or a bad standoff- this is good stuff cause I've seen it happen a number of times), and lastly for this post, make sure your RAM is good. Once, I got a bad stick of RAM and it crashed my computer quickly.

 

I did not mean to insult you but you should also not assume I am a first time builder. I am getting my dad to look at it then if he can't figure it out he knows a few guys who know computers like the back of their hands and they will figure it out. Thanks for your suggestions anyways.

 

Your problem could very well be the PSU.
I'm just woundering, is your PSU a Sparkle Fortron? Generally known to be very good PSU's
Or as you named it Sparkling Power, if thats the name I suspect Generic Garbage? if thats the case I'll bet thats your problem.

Either way what's more important than just 400 watts is how many amps on the + 12 volt rails (Today computer systems need's PSU's that can deliver over 30amps on the +12 volt rails)
Regardless of the brand a PSU test is in order.

Ya might make sure nothing is grounded out, Could be a short.
New MOBO? Is your standoffs installed correctly?
Check for loose screws, skinned wires etc.




Just an FYI
Thermal paste or thermal pad is critical component & is key to controlling temps.
Thermal paste is better than thermal pad.
Too much or too little can make temps sky rocket.
You also mentioned touching your thermal pad, oils from your skin can contaminate & reduce thermal capibilities, you shouldnt touch it.
Even peoples who install cpu/Thermal paste 100's of times still make mistakes on ocassion and have to reapply
You also memtioned "thermal paste is already applied to the heatsink by the manufacturer therefore making putting the thermal paste on idiot proof" How do you know if the guy who applied it or was running a machine that applied it wasnt an Idiot?
Just cause it was preapplied doesnt make it applied correctly.

 

The PSU is Sparkle Power. A chinese company. You can find the website at: www.sparklepower.com. I looked at the Amperage and none of the power supplies go over 30 amps on 12 volts.

Which brand of power supply do you recommend that won't cost too much but will still do the job.

 

If its powering off before POST completes, you are almost guaranteed thats the PSU. You can pick up a PSU tester fairly cheap from a place like CompUSA.

http://www.compusa.com/products/product_info.asp?product_code=317139&pfp=SEARCH

A multimeter will do the job, too (arguably better).

Don't forget, we know computers like the back of our hands, too.

 

What a great little tool, and cheap!

Many thanks, I've been looking for something like this for a while as I'm not intelligent enough to use a multimeter.

 

Thanks for your help guys, I'll look more at it today when i goto my dad's today. Wish me luck.