I have a Asus A78NX Deluxe Motherboard with AMD Athlon XP 2400, 512MB DDR400, 80GB HDD, 20GB HDD, 350watt PSU, DVD RW. I have just recently moved everything into a new case, and as far as I can see everything seems fine. When I plugged the powe cable into the back of the PSU, the pc turns on automatically, and the power button on the case does nothing but reset the computer. The only way I can get it to turn off is to switch off the PSU. I have looked in the motherbpard manual over and over to make sure everything it set up right, and I have even taken it all to bits and re-assembled it. Anyone got any suggestions??

Thx,

Big Cal

Hi bigcal27, welcome to SAF

Have you considered the possibility that the front panel on/off switch is plugged into the reset header on the motherboard?

Not sure that that could be the reason, as the case used to be my brothers, and all I did was put my stuff into it, and it was working fine when he had it.

thx for the advice tho

If you connected the on/off switch to the Reset pins on the "front panel" header you will get EXACTLY what you're describing.

Look in your manual and see the pinout descriptions for the front panel connectors which will be:

1. Power on/off
2. Power LED
3. Reset
4. HD LED
5. Speaker
6. etc.

That was one of the first things I did, and it all seems to be the same as the manual to both me and my brother. This kind of stuff happens to me all the time, god i hate computers

cheers for the help,

Big Cal

Okay, try this:

Power down.

Disconnect the RESET plug from the mainboard socket.

Disconnect the ON/OFF plug off the mainboard socket. Now you see the two little prongs of the socket, right?

Turn your Power Supply switch to ON. The unit should NOT power up at this point because both switches are disconnected at the mainboard.

Take a screwdriver and short the two prongs on the ON/OFF socket on the mainboard. Does the computer start up? After it has started, short the two prong again, and it should shut down.
> IF the computer does start up, you have a bad switch on your front panel, OR you have the leads from the two switches in question reversed as Alfons said above.
> IF the computer does not start up, you have a bad socket or defective mainboard socket.

QUOTE

Okay, try this: Power down. Disconnect the RESET plug from the mainboard socket. Disconnect the ON/OFF plug off the mainboard socket. Now you see the two little prongs of the socket, right? Turn your Power Supply switch to ON. The unit should NOT power up at this point because both switches are disconnected at the mainboard. Take a screwdriver and short the two prongs on the ON/OFF socket on the mainboard. Does the computer start up? After it has started, short the two prong again, and it should shut down. > IF the computer does start up, you have a bad switch on your front panel, OR you have the leads from the two switches in question reversed as Alfons said above. > IF the computer does not start up, you have a bad socket or defective mainboard socket.

Took out both the reset and on/off plug from the motherboard, but as soon as i turn the PSU on, the pc starts up straight away without me pressing anything, or even having the on/off switch connected to the motherboard.

Sounds like a short-circuit somewhere, probably under your mobo. Are you sure it is properly seated on its plastic spacers and not touching the metal case ?

Chris