Computer switches itself off and on

[veledrom]

Hi,

I recently build a desktop computer. As soon as I switch it on, it switches itself off for 3 seconds and after, switches itself on!!! Nothing has been installed yet. No Windows or nothing.

What could it be the case?

Also, the graphics card is as hot as fire without even having Windows on it. I just turn the machine on and go to BIOS, it turns into heat machine. VGA requires about 400W. I connect 4 pin mains to the board not 6 pins.

Thanks

ASUS 1155 P8P67-M PRO REV 3.0 M-ATX
Intel Sandybridge i5-2500K Unlocked Core i5 Quad-Core Processor (3.30GHz, 6MB Cache, Socket 1155)
Corsair CMX4GX3M2A1600C9 XMS3 4GB (2 x 2GB) DDR3 SDRAM Memory
Corsair CSSD-F60GB3-Bk Force Series 3 60GB Solid State Drive
Sapphire 11166-02-20R HD 5450 1GB DDR3 PCIE HDMI Graphics Card
LG GH22NS50.AUAA 22x SATA DVDRW Drive
600W PSU

[cwarn23]

By the sounds of it, it seems like you might need a larger power supply but perhaps you should add up the wattage figures first. I know off by hand that the cpu is 130 watts. And if the VGA is 400 watts then that leaves you with 70 watts to power the rest of the computer. Also lack of wattage may have damaged some components in the computer so you may need to check piece by piece for falts when an appropriate power supply is added. This can be done by for example taking out the graphics card and booting up to see if there are any bios sounds and same with graphics card in and repeat with each piece except the motherboard and at all times when testing keep at least one ram chip in.

[veledrom]

I'try what you said but actually PSU is 650W. I've given wrong info before.

It only happens when I push the power button first time to run the computer. I installed Win7 and nothing happens when I am in Windows.

http://www.ebay.co.uk/itm/Alpine-650W-Quiet-Silent-PC-Power-Supply-PSU-Black-Red-/360371284443?pt=UK_Computing_PowerSupplies_EH&hash=item53e7cd69db

[cwarn23]

I've just done the math and your power supply appears to be the right size. Also does the fan on your graphics card spin because that would indicate if power is going to the graphics.

Motherboard: 15W
CPU:         95W
RAM:          4W
SSD Drive:  2.5W
Graphics:   450W
CD-ROM:      25W

I also noticed the following:I connect 4 pin mains to the board not 6 pins.
There are 6 pins for a reason. Perhaps you should find the correct cord or adaptor. That could be the source of the problem.

[Mohammed Ammar]

Please describe your problem in brief i doesn't understand.

[veledrom]

6pins main doesn't run the computer I tested before. I took all the parts out and tested one by one. No joy.

Solution:
Board has a switch called "MemOK!". If the computer started with it first time, it displays a message on the start up which says "You memory has been successfully registered..... go to BIOS and save changes.....". That's it. Problem goes away just like in my case.