I thought it would be fun building a new PC why?

I bought all the parts, put them together, and…nothing. :frowning:

This isn’t my first time assembling a computer. It’s my third full assemble, and I’ve done loads of upgrades, replacements, adding parts, etc…My first build was the only one that never had any problems. The second one went wrong because of a bad hard drive (I originally thought the MOBO had a SATA problem, but it was the SATA drive.) This one…I have no idea.

Nothing happens when I press the button. Nothing at all. No fans go, no lights turn on, no beeps. Everything from the power supply is plugged in. The ATX power connector, the extra 12v CPU connector, the PCI-E power connector for the video card, and even an extra MOLEX power connector on the mobo that it says is only needed if I have SLi, but when nothing worked, I tried that too.

The power switch is plugged in the right spot, and I even unplugged it and shorted out the connectors to see if the switch was dead…nothing. The mobo isn’t shorted out to anything, every standoff screw I put into the chassis was used, so that’s fine. I removed all the cards and cables, including the CPU, and put the all back in…still nothing.

The only thing I can think of that could be bad is the power supply, but I have no way to either test it or a spare PSU I can use (I know my current PC’s PSU doesn’t have PCI-E connectors (thought the vid card came with a molex adapter,) but I know it doesn’t have the right ATX power connector (the new one has four extra pins.)

Does my analysis of the problem seem accurate? There is a small LED behind the power switch on the back of the PSU, and it does turn on, so it’s getting power, and can do something with it, but I have no way of knowing if it’s getting to the mobo.

I had a similar problem last time I built a PC - the power supply LED turned on, but nothing happened. It was the power supply. Maybe you can still exchange it at the store?

The “store” is Newegg. Good return policy, yes, but God damn it that delays the new PC by another week…and that’s if it IS the PSU. I just want to make sure I’m not missing anything before I begin the process of RMAing things (especially if it’s the wrong thing…cause let’s face it, it could be the mobo…I think I need to find a friend with a PSU I can borrow.)

Could you try the new power supply in the old computer?

No. As I said, there are 4 extra pins on the ATX connector with the new PSU, so it won’t fit onto my current mobo’s connector.

You clearly illustrate the reason why I no longer build PCs, and cringe every time someone tells someone else to “just build one” instead of buying one. Sure, you can do it. Yes, you might save some money. But in my experience, it has rarely been enough money to overcome the hassles of building one myself, or giving up the convenience of a support phone number.

Can you pick up a PSU tester locally?

Hiya. It is possible to test the PSU without and extra equipment. Current PC power supplies will only turn on when there is a load on the PSU. Not sure why but it’s been like this for a few years.

One option if you are comfortable is to briefly ground the load sense to see if the PSU fan starts. This obviously needs to be carried out with the PSU isolated from your very expensive bits of silicon.

Disconnect all PSU connectors from the mobo. Strip the ends of a small length of wire (it’s not going to carry much current but a spare bit of mains cable would be ideal) and on the main power connector (which fits into the mobo) locate a socket hole which is fed from a black wire - this is ground. Push one end of the wire in here and put the other end into the socket hole which is fed by the green wire. If the PSU is plugged into the wall it should start to spin the fan.

If this doesn’t happen, check and re-check that the PSU is plugged in and that the jumper wire is defintely making contact to both the green and black wires. If nothing happens then you have a dead PSU.


Have you tried toggling the voltage switch on the power supply?

I just did the same thing and hadn’t previously used an ATX2 power supply.

I had stupidly inserted the four-pin ‘extension’ plug in after the main 20-pin plug. Wasn’t making contact. Motherboard LED came on but nothing more.
Closer examination of the plug revealed that the four pin had to be fitted first, followed by the 20-pin. All was well after that.

I have another machine waiting to be rebuilt because somebody’s dad did just that.

I did this, and the PSU started up (and I attached a couple cans fans to the PSU as well and they spun just fine. Don’t worry, nothing else was attached to the PSU.)

So it looks like there’s something with the motherboard? Or maybe the CPU?

OK. At least the PSU is delivering juice. In the past I had an identical problem and it turned out I’d jammed the reset switch whilst fitting the case. I would suggest taking the mobo out, disconnecting all peripherals and trying to power it up.

I would have the PSU plugged into the mobo and just the case on/off button connected to the board. Maybe connect the CPU fan to the mobo connector and try that. If it works carry on adding components to the mobo (CPU, RAM etc) until it stops. If it all continues to work try mounting it back in the case.

Let us know how you go.


Next step is to try powering up the components without the motherboard being installed in the case, so you can rule out pin-to-case grounding problems. You will need the case nearby so that you can connect the power switch. You can also install the motherboard in the case with a sheet of cardboard between the motherboard and case, to be certain you never develop that problem.

For bonus points, connect the bare minimum number of components:

  • motherboard
  • CPU + heatsink
  • one stick of RAM only
  • video card only if mobo doesn’t have onboard video
  • monitor

You don’t even need a hard drive or keyboard at this point. A successful boot will give you a working video display telling you what you know: there’s no HDD or keyboard connected! :smiley:

At that point you can add devices one at a time to determine what’s wrong.

Reseat the cpu, because the MB won’t do anything if the cpu doesn’t work. No execution of the Bios so no beep codes at all.

I’ve built 4 PC’s myself, and they’ve been more stable than any pre-built system I’ve ever owned. Sure, sometimes when things go screwy, you can get frustrated, but you save SO much money that it’s not really worth it to me to do otherwise (my current Core2Duo machine cost me $600…the comparable system from Dell was $1050 at the time of purchase. )