Motherboard won't start at 115v, will start at 230v? Uh.. help please.

[RumZ]

Okay, so hello there, I was referred to this website from a friend.

I have a very unique problem, at least to my knowledge, that is foreign to me.

Recently I bought:

http://www.newegg.com/Product/Produc...tent-_-text-_-

and

http://www.newegg.com/Product/Product.aspx?Item=N82E16817152042



I got the motherboard, and something strange occurred, I went to test it with the power supply to make sure it started, and the light for the power supply would turn on, than turn off shortly after. This was a repeating cycle from simply pressing the power button on the motherboard (It has an on board power switch,) once.

Now, this is where it gets really odd. I assumed there was an issue with the motherboard, but when I turn the power supply's voltage switch to 230v the blue light spins up on the power supply, the lights on the mobo turn and stay green, and as far as I know everything is fine.

But I have to wonder, is this safe? Is this normal in some cases? I live in america, I'm not plugging the thing into a 220/230 volt line, my house is at 115. This all seems quite odd to me.

And if this is acceptable... is this safe to leave like this?

So many questions, the last thing I want to do is to jump into this, assume it's okay, and watch my computer explode before my eyes.

Looking forward to opinions and responses... until than, the rig I'm building is sitting in it's place, and I'm not even going to attempt to plug it in.

 

[bigpow]

motherboards use DC voltage, not AC.
It doesn't matter what's your line voltage, as long as your power supply can support it.
Some power supply supports auto voltage (wide range), others not. Some have switch selector for 110/220V AC.

From what you described, it's hard to determine what is the culprit. I recommend basic troubleshooting tricks: swap components to find out which one broke it.

 

[RumZ]

All that was plugged in was the motherboard and the power supply.. I tried three different power supplies. I got another motherboard from newegg today on a fast RMA, same result.

It's too bad too, that mobo is really sexy for what it has and the price I got it.

I ended up returning for a full refund.. going to try a Biostar now.

 

[jackschmittusa]

Never heard of testing a mb without a cpu in it, so I have no idea how it should react.

What would possess you to change the psu switch? I seem to remember a friend killing a rig doing that years ago.

I always recommend bench testing but I use 1 stick of ram, cpu, hsf, and video (built in or card). I have a monitor and kb attached and do my initial BIOS setup at that time as well.

 

[mrblotto]

maybe the switch on the back of the PS was put on backwards at the factory?
Check the volts on the PS using a multimeter? (I think that's what they're called)

*shrugs*

 

[Diogenes2]

Never heard of testing a mb without a cpu in it, so I have no idea how it should react.

What would possess you to change the psu switch? I seem to remember a friend killing a rig doing that years ago.

....

Changing the PSU switch from 110 - to 220 with a 110 source shouldn't hurt anything .. It results in lower output voltages if any at all ..

Now, switching to 110 with a 220 source is a different story ...

 

[Modelworks]

The switch from 220 to 110 on ATX supplies with switches use 220VAC internally. When you switch it to 110VAC on a power supply it changes the connections so that the rectifier stage works as a voltage doubler. If you set it to 220VAC then the rectifier stage works like normal. Either way the supply is using 220VAC internally or roughly 311VDC.

Using the switch in the 220V position on a 110V outlet is bad. The reason is because that only provides 155VDC. So to make up for the difference the supply will put a heavier load on the internal parts like the mosfet , generating more heat and the supply will not be capable of reaching its rating without damage. It might not quit that minute but doing it long term will destroy it.

If the supply will not work when set to 110V and you have tried a different supply then the first thing I would do is use a meter to test the wall outlet using the picture below. Between the red + blue on an outlet there should be 110-125VAC. From the red to the green should be 110-125VAC and from the blue to the green should be 0VAC.