building a pc first time help!

so this is the first time i built a pc, and heres the problem im having;

when i turn the pc on it doesn't detect anything it just turns on with a lousy noise and it stays like that so i have to turn it off holding the power button. i then noticed that i was missing the ATX 2 x 4-pin EATX12V cable so i connect it and whenever i connect that cable the PC doesn't even power on.

my question is, does this atx 2 x 4-pin 12v cable must be connected for the pc to be working? or is it like optional, i don't understand why when i plug it in the pc won't power on and my power supply is 750w i think thats enough.

IS IT THE POWER SUPPLY THE PROBLEM OR SOMETHING ELSE?

-------HERES WHAT I GOT ----------

-asus p5n-t deluxe motherboard Link:

http://www.google.com/products/cata...result&resnum=3&ved=0CBIQ8wIwAg&os=tech-specs

-LSP ULTRA 750S ATX POWER SUPPLY

-intel core 2 quad Q8300

-nvidia geforce 9800 GT

and im using the hard drives from my old computer
Gateway GT5238E, http://support.gateway.com/s/PC/R/1009189/1009189sp2.shtml

 

plz help!

 

Hi solito,

First off, you can't use the HD from another computer as it doesn't have the drivers needed for the new motherboard.

Second, are you using a SATA or ATA drive?

Third, have you gone into the BIOS and set the second or third Boot Device to HD0? The first boot device should always be either your floppy drive or your CD\DVD drive.

Try using a formatted, blank drive, and boot to your OS disk and see if it will install.

And, yes, you need both the 24-pin and the 4-pin connectors for the MoBo.

Try: 1) Hookup a blank formatted drive jumpered to Master; 2) Turn on computer and keep hitting the Del key (or whatever key your MoBo requires) to get to the BIOS; Set the First Boot Device to CD\DVD and the second to HD0 (that's a zero) and select "Auto Detect "; save the settings and before you close out of the BIOS, insert your OS Disk; 3) close out of the BIOS and the computer should boot to the CD\DVD drive and you should see the install window for your OS.

 

hi chris ty 4 replaying,


you said i have to connect both but when i connect the 4-pin connector the pc won't start, is this a power supply problem or not? no matter what i do the pc doesn't start i have to remove it back and leave the 24-pin only and then it will start but with the same problem as it starts but it doesnt detect anything and the power supply makes a really lousy noise until i turn it off.

i cant access the bios too it doesnt detect the monitor


and im using a ATA drive

 

If your PSU is making a noise other than the whirr of the fan(s), that might be the first thing to test — and why you can't get to the BIOS.

 

because when i connect the 4-pin cable the pc doesn't power on i mean it doesnt do anything! and when i UNPLUG the 4-pin it starts but for some reason it doesnt detect anything and i can't get it to display, and the power supply or the heat sink makes continiusly lousy noise.

do u think i should buy a blank hard drive and a new power supply?

 

Hi solito,

The PSU and the "heat sink" are two different animals. Your heat sink is associated with your CPU. If it's making noise, then it's not seated properly. If it's just the PSU making the noise, then the finger points to it; and if it's bad, then yes, it needs to be replaced.

What does your MoBo manual say about the 4\24-pin connectors?

 

Any Computer store can test the Power supply,

 

Hi Solito, Did you read your Motherboard Manual correctly? I would suggest you very carefully re-check all your installation as it sounds like as jpChris has stated, your CPU and Heat sink and cooling fan might be the trouble. I trust you have thermal paste/pad installed between CPU and heatsink?

You will have to install your Motherboard Drivers if you can get a basic start.
But I would strongly suggest a re-read of the manual. Neil.