Motherboard power issue

I have motherboard. All connected properly. the light on the board lights up, to show there is power going to the board, but when I press the power button to turn it on, nothing happens.

I have tried inserting the board into other cases and using their front panel connectors, have found the same issue.

The cable from the case to the power is in the correct pins on the board (as read in manual), but nothing works.

Although the motherboard light is on to indicate the power is going to the motherboard (from power supply), I cannot turn the board on. I know it isn't the power button (tried other case etc)..and the manual says to use at least 300w power supply. I have tried a 300 and 450.

what could it be?

 

Just a shot. I notice you mention the "cable". Usually there are 2 power cables for a motherbord.

Also, you should try minimum configuration setup. Just motherboard, VGA , 1 or 2 banks of RAM only.

It is also possible, that the motherboard is defective despite getting power. 6 months ago i got new motherboard, fans spinning, but no boot. RMAed it.

 

A friend of mine had this problem recently when he put a new crate together. Turns out he only plugged in the 24-pin cable to the mobo and forgot to plug in the 4-pin power cable for the CPU. That's the small square one with two rows of two. See if that's plugged in properly. This applies to Intel CPUs, don't know if the newer AMDs have this plug, the older ones don't.

 

Both the standard power and the AUX (4 pin cube shaped) power leads are inserted correctly into the motherboard.

There is one RAM chip, one hard disk, the very basics. Even tried both using onboard video (without an add on video card), and with added on PC X video card.

Even without a HDD, the board does not turn on.

 

Is this motherboard new or used? If it's new you might want to return it.

If you've already used it before with no problems it might be fried. Otherwise check that all the components are compatible, i.e., the motherboard supports the CPU and make sure the memory is the right type. This weekend I installed two additional memory DIMMS and had the same situation. Turns out that I can only use all four memory slots if all the chips are single-sided. Of course you are only using one memory stick, but check to be sure it's the proper type or try a different one to rule that out.

 

Check that the CPU cooler fan is connected properly to the motherboard.
You might also want to make sure that the cooler itself is properly installed.
Good luck.

 

That only indicates the ATX required +5Vsb standby voltage is present. It does NOT mean all the necessary voltages (to include the regular +5V, +12V or +3.3V) are present. This motherboard light is more a warning to users to UNPLUG the supply from the wall before doing something inside, like insert or remove RAM, or other hardware.

Most newer motherboards have an 8-pin ATX power connector for the CPU, in addition to the normal 20/24 pin power connector. Some older boards require an additional 4-pin instead of 8. Check your motherboard manual carefully.