What did I do wrong here?

[MysteryBowler]

Lucky me, a faulty mobo wound up causing a direct short and taking out itself, my old 250w power supply and a hard drive. Hmm....seems like time to upgrade. 🙂

After receiving/purchasing all the parts I need, I set to the task of assembling the PC. Mind you, it's been since...eh....'95 😱 that I've put together a PC from all-seperate pieces, but I figured I needed a refresher course.

Starting with an empty ATX case, I mounted the mobo, set the processor (Athlon XP 2400+) and put in the new 450w power supply. Put in the RAM, hard drive, video card, etc. All pieces were installed and connected before I ever connected the power to the back of the machine.

After double-checking everything, I connected the power and *click*....

Nothing.

*click*

Nothing.

I won't go into detail about the number of clicks. But it turns out that I had the reset switch hooked to where the power switch needed to be. Heh. My mistake. I corrected that and *click*

:: Wrrrrr.....:: Power's on! :: Ehhh....:: Shut down. Not two seconds later, as it turns out.

I've got a sinking feeling that it's the switch. From what I understand about ATX power supplies, they require a momentary contact switch (normally open, normally closed? I forget...). Would the behavior of powering on for a moment and then - before the mobo ever gets going - turning right back off be consistent with having the wrong kind of switch?

Thanks in advance for any help anyone can provide!

 

[agnitrate]

Originally posted by: MysteryBowler

:: Wrrrrr.....:: Power's on! :: Ehhh....:: Shut down. Not two seconds later, as it turns out.

I HATE when this happens. It's happened to me a few times. The reason it usually happens to me is because I plug the HSF cable into the wrong HSF header and it doesn't detect it upon startup. The motherboard usually checks HSF1 to make sure there's a fan there so it won't fry it and therefore turns off after about a second if it's not detected. So make sure you have it in the first header and not the second one. Consult your manual if you can't read it on the mobo because it's not always the closest one (why it always gets me).

Secondly, try resetting your cmos jumper on the board and see if that helps any. Turn off automatically usually means something isn't working as it should so it fail-safes to off.

Let us know what you come up with.

-silver

 

[jackschmittusa]

I agree with agnitrate. If not the hsf plugged into the wrong header, then maybe a short between the mobo and the case. It is not the switch. The switch is a N/O momentary contact type. Once you depress it and let go for the startup, it is out of the picture. You can start a mobo up on the bench by shorting the 2 pins used for the switch with a screwdriver.

 

[zerocool1]

ya that happend to me yesterday then I remember the thing in bios that says that you need the hsf power in the correct header