Asus p8z68-v pro won't post

[led-zeppalike]

Hello,

Just got all the bits for my new build today (some new, some used, some I already had).

Asus p8z68-v Pro
Intel i7-2600k
Kingston HyperX 1600 2x4GB
HIS 6950 2GB
Corsair vx550

Anyway, I put it all together and it won't post. There are no beeps (I've got the speak plugged in), there are also no LEDs. The fan on the heatsink (freezer 13 pro) spins for about a second, then stops.

The only lights are a green power symbol button on the motherboard (I press this to try and start the computer) and a red restart button, although the colours might be the other way around, I forget. I've tried pressing and holding the RAM button; it flashes red once if there's ram in there, the fan spins for about a second then stops.

Both power cables are plugged in. I've tried with and without memory, as well as with just 1 stick. Tried with and without the processor. Tried with and without graphics card. I've tried testing it with the board on an antistatic surface to avoid a short circuit, and with the PSU and the motherboard on an antistatic surface; same results.


The power supply should be fine as it was in my old (current) PC this morning and working fine. However, when I tried putting my old PC back together after I failed with the new one, the old one won't post either. For reference it's a GA-P35-DS3P and again, was fine earlier this morning and for the past 2 years. The old PC has the same problem: no LEDs, no beeps and fans spin for about a second.


What are your opinions? Is the power supply at fault? Could it have been damaged during transition between cases? I got my father who has a degree in electrical engineering (so I guess he knows what he's looking for) to have a look at the inside of the power supply, he said he couldn't see anything obviously wrong with it.


TIA








EDIT: Turns out it was a dead power supply, swapping it for a working 850 watt one made it spring back into life.

 

[suteck]

That would be my guess. The video card specs say "500 Watt or greater power supply with two 750W 6-pin PCI Express power connectors recommended". That only left 50w for everything else. Your 2600K takes Max TDP 95 W during max load and I think during startup it uses pretty close to all that, however briefly. So you probably sucked all the juice right out of the psu. If it won't start the old computer anymore that's just further proof that it's probably the psu.

 

[ko888]

A single Radeon HD 6950 reference clocked graphics card will draw less than 17 Amps from the +12 Volt rail under a full GPU load (i.e. running FurMark or GPU Stress Test in GPU : OCCT).

For a single Radeon HD 6950 reference clocked graphics card a power supply with a minimum of 500 Watts or greater with a +12 Volt continuous current rating of 30 Amps or greater and with at least two 75 Watt 6-pin PCI Express supplementary power connectors is recommended.

The Corsair Enthusiast Series VX550 (CMPSU-550VX) PSU, with its +12 Volt continuous current rating of 41 Amps, more than meets the requirements.

I would suggest checking the voltages on the power supply using a multimeter. If the +12 Volt rail is dead or if the voltage is not operating within specifications the CPU will not receive proper power to even start up. Fans may still spin and lights will light up because they are on a separate power circuit from the CPU's VRM power circuit.

If there is a problem with the power supply then have it RMA'd if it's still within its warranty period (5 Years for the CMPSU-550VX).

 

[led-zeppalike]

Thanks for the replies. I've come to the conclusion that it must be the power supply since it's the only common component. I tried the 'paperclip' trick this morning to test the PSU without the motherboard... it does the same thing, so I'm 99% sure it's that, hopefully it's just that.

I've ordered an 850w PSU (may be interested in crossfire in the near future), and am currently pursuing the RMA process with Corsair.

Thanks