10 replies to this topic

[teknix360]

I am building a new system today and got my core components connected. I went to do the test boot, but it won't power on. The PSU fan doesn't even spin, there is no noise, so I don't think it is drawing power. Is there a way to check?

My parts:

• CPU: Intel Core i3-3225
  
• Motherboard: ASRock H77M Micro ATX LGA1155
  
• Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600
  
• Power Supply: Corsair Builder 500W 80 PLUS Bronze Certified ATX12V

I'm just an enthusiast, not an expert so forgive my non-technical terms here. This is what I have done:

• Installed CPU
  
• Installed CPU Fan, pushed pins down and connected CPU Fan plug to mobo
  
• Plugged in the big long ATX plug and the CPU plug (it's got 6 pins) from PSU to mobo
  
• Installed the 2 sticks of RAM

Then I connected the PSU power plug from the PSU to the wall and flipped the switch. Nothing. I re-check to make sure everything was seated properly, and it is as far as I can tell. I tried a different power plug and a different outlet, but still nothing.

I don't have another PSU to test with.

I read something about CMOS jumpers, but I don't know exactly what that does and if it would help.

This is only my second build. On my last build, everything worked fine, so I'm not sure what DOA parts are like. I'm thinking my PSU is a dud, but not sure.

What else can I try?

[Biohead]

Shouldn't the CPU connector be either 4 pin or 8 pin - not heard of a 6 pin before? You didn't plug in a PCIe power connector to it did you?

They should be keyed to prevent this, but a bit of force easily bypasses this.

[metallithrax]

Can you use the power cord to power something else? If it works, then it could well be(or most likely is) the PSU.

[Dead'Soul]

A simple way to test a PSU is short circuiting green and one of the black lines on the main power cable. It's fan must start. If not, PSU is faulty.

[B.Wolken]

Biohead, on 09 February 2013 - 18:52, said:

Shouldn't the CPU connector be either 4 pin or 8 pin - not heard of a 6 pin before? You didn't plug in a PCIe power connector to it did you?

This. I've never seen a 6-pin CPU connector. PCIe connectors have 6 pins.

[Detection]

Did you connect the front panel pins to the motherboard?

If not, then the power switch on the case is connected to nothing

[Guth]

Detection, on 09 February 2013 - 19:04, said:

Did you connect the front panel pins to the motherboard?

If not, then the power switch on the case is connected to nothing

this, you dont mention connecting the case switches to the mobo

also I just wanted to throw this out there, I had a system I built that wouldn't power on and I couldnt figure it out. IT turned out that when I installed the mobo, i couldnt get a few screws in so I left them out and the mobo wasn't properly earthed and therefore wouldn't power on! (dont know how because I did have most screws in but after putting in the other 2 I missed, it booted first time)

[alwaysonacoffebreak]

Can't be because of the screwes not earthed. That's pure bull.

[ajcdotme]

Biohead, on 09 February 2013 - 18:52, said:

Shouldn't the CPU connector be either 4 pin or 8 pin - not heard of a 6 pin before? You didn't plug in a PCIe power connector to it did you?

They should be keyed to prevent this, but a bit of force easily bypasses this.

Even if shorted on the wrong cpu connector, it should still power up and spin the fans. A mobo should turn over with no valid cpu, but depending on the chipset, it may or may not attempt to post.

I'd short the pins on the psu (with EVERYTHING ELSE disconnected) and see if the fan engages. If it does, I'd attempt to power the board with no cpu or ram (hold the power button down for a period of time here to flush ramdac/caches. possibly manually short the power jumpers on the mobo for a second to power the board to ensure your issue is not a bad power switch)

If all this works, I'd power it off, pull the power, then depress the power button or short the power jumpers with no wall power to flush voltages stored in capacitors. Mount cpu/ram and attempt a POST.

Reply and let us know the progress on these tests?

[1941]

B.Wolken, on 09 February 2013 - 18:58, said:

This. I've never seen a 6-pin CPU connector. PCIe connectors have 6 pins.

Below is a picture of his cabling from his CPU it is 8 Pin. A square box around it.

[teknix360]

Biohead, on 09 February 2013 - 18:52, said:

Shouldn't the CPU connector be either 4 pin or 8 pin - not heard of a 6 pin before?

Whoopsie! You're correct. It's an 8-pin! I was typing the post from memory.

Guth, on 09 February 2013 - 19:08, said:

this, you dont mention connecting the case switches to the mobo

That was it! I was trying to just boot from outside the box (with just mobo, CPU, RAM, and PSU). I was just flipping the power switch on the PSU and nothing was happening. I connected the front panel power switch plug and it booted right up!

The build I did last year had a power button right on the mobo. It's been so long though, I didn't realize I was missing such an obvious step.
Thanks so much for the help, everyone! I knew you all would figure it out.