will a mother board not turn on if the computer power source if lower than its rating?

i recently built a new gaming computer that's really awesome, but i won't turn on. i have assembled many computers and know everything is plugged in properly but when everything is turned on nothing happens, even the red light on the mother board won't go on. my mother board says it needs 500W and my power source is 450W could this be the cause?

UziMonkey8 years ago
When troubleshooting a computer, start simple. Take everything out and leave only the power supply, motherboard, CPU and RAM. Make sure you've plugged all power into the motherboard, this includes the ATX 20+4 main connector, and the 4-pin 12v connector. Make sure the front panel switches and LEDs are connected correctly as well.

If it still doesn't turn on that this point, either you've done something very wrong or something is broken. The easiest way to determine which part is broken is to try alternate parts.

The rating on a power supply is the maximum wattage it can supply. When buying a power supply, you have to assume the manufacturer has inflated this number. Your 450W power supply, especially if it's a cheap one, probably won't supply 450W for long before failing. If your system needs 500W, you should get at least a 550W or higher.

Another note about power supplies: don't even bother buying cheap ones. A cheap power supply will try to get by using less voltage regulators, smaller heat sinks on the regulators (these things get really hot) and less filtering capacitors. Cheap power supplies just aren't worth it. Good power supplies have multiple regulators and are heavy from all the heatsinks and filtering capacitors inside.

Power supplies also can conceivably fail catastrophically, damaging other components. If they're only partially failing, they can also cause strange and seemingly random system instability. Along with cheap RAM, a cheap power supply is one of the causes of random blue screens, reboots and lockups. I'll say it again, just don't bother with cheap power supplies.
110100101108 years ago
probably not. it takes really high watts only when in game. and yet i dont think it gets over 450 W are the board and power supply ok ? is the battery on the board ok ? some boards dont power up with bad battery