Won't Power On!!! Help!!!

Hey guys,
I'm so frustrated!!!! I'm a software guy, and I dont do much hardware so i'm lost. A couple days ago I left my box on overnight to defragment, and the next morning everything was frozen, so i rebooted and Win2k said i had a bad fastfat.sys orr something so i reformatted the drive on another box and put a clean 2k on it. So when i stuck the HD back into my box, and pressed the power button, my power button flashed and then went off. I usually have to unplug the power supply and wait before i try again, but its just not working!!!!! I have a VIA 8605 Mainboard with 256mb Ram. I disconnected all other accessories like Cdrom, Zip, etc. still wont work. HELP ME PLEASE!!!!
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Try replacing the PSU if you can.
It sounds very much like your PSU doesn't like the night shift.
Also check all leads are connected properly
It is either a failed PSU or a problem Mobo, the PSU is easier & cheaper to troubleshoot so start there.
If you have another system, try taking the PSU out of that & see if it powers up the the sick system.
good luck
Check this

Windows 2000 could not start because FastFat.sys is missing or corrupt?

Also try having the latest servive pack for your windows 2000

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Level10AccessAuthor Commented:
Thats not the prob, i reformatted already, Im wondering about my mainboard not powering up.
Level10AccessAuthor Commented:
let me rephrase. My motherboard is not powering up and i dont know why. I gave you the info on that fastfat.sys error because i thought that might have led up to the problem i have now. sorry
Do you get any thing such as fans or anything? Or just dead altogether nothing?
If you get nothing check the power switch to motherboard connection. If that connection is good you may have a dead power supply or switch. To test switch change on the motherboard the reset button to test. They are both momentary switches normal open like a doorbell button. If you get just fans running and no POST you could also have a dead power supply.

The fans run on 12v the power supply has 3 voltages 12v 5v and 3.3v. If you loose the 5v or 3.3v it can still act as if it is powering up.  What happens is you don't get power to ram vga or cpu. this is why when the PSU dies or is weak you usually don't get any post warning beeps or video.

limited simple test.

 Power supply tester.

you sure that IDE cable was put back correctly when you replaced the drive?
check all those cables, you might have disturbed something when you moved the drive.
You should do some tests on your equipment. Get a another computer, or the one you posted this with, and switch things around. My bet is it's the powersupply and the fastfat.sys was a symptom or seperate. Just swap your powersupply into the other computer. If it doesn't work then it's the power supply.
I had a similar problem but I fixed it by taking off some of my peripherals.
Do you have a line conditioning device on your computer. Could there have been a power surge?
If it's not the Power Supply then it's probably the Mobo. Check all connections, the powersupply to mobo conmector and such. If the Mobo is fried you might as well buy a new computer. The CPU is probably gone too if you lost the Mobo.

If you're running Win2k I guess your computer isn't too old and I don't think it broke down from simple self inflected failure. I bet somthing happened overnight.
1st thing is always to look at what changed. It is possible to put the IDE cable on backwards, cockeyed etc.
(colored stripe goes toward power connector)
Reseat all your cards and memory.

The full drill would be to disconnect eveything from the mobo, all cards except video , drives, keyboard, mouse, printers, usb devices, etc. Leave 1 memory module in and try to boot. At that point if you can't remove the video card, you should get a beep error on the mobo speaker - if not, replace the video card and remove the memory, if no beep code at that point it's the processor, power supply, or motherboard.

If you dislodged you processor heat sink or stalled the fan with an errant cable, they can fry pretty quickly (a few seconds to a minute).

it is very possible that ur processor or ram has burnt out, try a diff pro/ram and c if tht wrks
Switch the PC off at the wall.
Unplug the power cord from the wall to the PC, remove it completelty.
Replace it.
Try turning your PC on, if nothing try another power cord.
If nothing, replace your power supply and try again.

Power supplys tend to just go pop, as you've described.
Because your getting no response to turning the PC on, indicates the power supply.
(90% likely).

If it was the CPU or motherboard the power would still come on, it wouldn't post or anything of course, but the fan on the power supply would still turn. Check that out and let me know.


A fried processor behaves exactly like that as does a shorted mobo
I would do same as chicagoan suggested bare the mobo from everything except the processor then:
 power up --> power down --> unplug or switch off from back --> power up again (to clear all power left in system) --> hookup RAM --> plugin & power up --> power down and switch off --> power up again to clear mobo --> hook up video card --> switch on + power up

I think you should get somthing but before baring the mobo you should try to just start without your HD that you formatted onthe other machine
Installing an OS on one box, then swapping the drive to a second box very seldom works.  
Level10AccessAuthor Commented:
Thanks for all your responses. I'm typing this on my restored system! It was my power supply. Congrats to those who got it right. Points headed your way. All my files i backed up i accidentally formatted ::kicks himself::, but fortunately i'm up and running. I went from a 250 Watt to a 400 to make sure it can handle all my hardware. Thanks for helping a harware idiot.

Cheers :)
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