STi8

Bought a pre-built and tested bundle (motherboard, processor and RAM) as the basis for a new PC. The processor is an Intel i7 4770. When I connect the power blocks and switch on the mains (not the power switch on the front panel) the CPU fan spins for a second or two and then nothing works. I have tried two PSUs (both 480w) with exactly the same result.

Any ideas anyone?

JDM_333

Sounds like a dodgy motherboard to me without being there to look at it. Have you checked all the connectors are in the right places? You should be able to download a copy of the motherboard manual online which will confirm what goes where wiring wise. I bought all the components to my current desktop years ago from overclockers.co.uk and built it myself and touch wood never ever had a problem except one dead power supply (dark power) surprisingly the overclockers own power supply has outlasted the more expensive dark power one!

jura11

iTrader: (7)

Hi there

Do you have correctly installed RAM ?

Usually on Asus board or others too,depends on how many sticks you are using,but if you are using 2 sticks,you should be have installed RAM in slots DIMM_A2 and DIMM_B2

I would try to boot with one RAM

Jura

Galifrey

iTrader: (3)

Yeah try with one stick of ram at a time, also have you connected the front panel power switch and tried that? The PSU switch alone will not turn the mobo on, you need to press the front panel power switch.

Galifrey

iTrader: (3)

Yeah try with one stick of ram at a time, also have you connected the front panel power switch and tried that? The PSU switch alone will not turn the mobo on, you need to press the front panel power switch.

Byte

If the motherboard is in the case, take it out, lay it on a work bench and connect the PSU to it. If it has onboard video connect that and a keyboard and use a small screwdriver or jumper to turn it on by 'joining' the power switch pins briefly. This will rule out any spurious 'in case' issues and let you troubleshoot the M/B and RAM. PSU only needs 24 pin and 4/8 pin connections at this stage too.

If the M/B still fails to POST then switch off at the mains and remove the CMOS battery or reset the CMOS using the jumper provided. Try again. If it still fails to POST then replace what you can (not much left now other than CPU, M/B or RAM)

Good luck

Evolution Stu

iTrader: (2)

Agreed.

STi8

Thanks for the suggestions. I am confident I connected everything correctly as per the manual. The motherboard is a Gigabyte. I started off connecting all the front panel wires and it started off by spinning the fan as soon as I switched on the rocker switch on the back of the case. Pressing the front panel power switch does nothing. I have re-seated the memory sticks but will try them one at a time to see if that works.

STi8

Have tried swapping out the memory sticks but still get the same result.

I think this is going back.

Thanks for the help.

Galifrey

iTrader: (3)

Have you tried reseating the CPU?

Byte

I've used Gigabyte motherboards for years and they are normally very reliable. Have you tried taking the board out of the case and working through the troubleshooting steps I suggested? It is a lot easier to trace a problem when all unnecessary items are removed from the equation.

Neanderthal

iTrader: (6)

Are you sure you've connected all the cables? I did the same as you a couple of years ago and experienced the same issue. Turned out I hadn't connected a 12v ATX cable (little two wired thing).

Ash170990

iTrader: (1)

sounds like motherboard to me, we always use gigabyte boards with our PC builds and have to say, recently we have had a couple of failures, doing exactly the same...

STi8

Tried all the tests you've suggested other than resetting the CMOS. First time I've bought a pre-built bundle and the last! The motherboard appears to be FUBAR and it's going back. Will update when I get back from holiday in a couple of weeks

_Meridian_

iTrader: (1)

This is usually a short circuit, and the hard bit is working out where. Remove everything except the CPU and cooler and try. You should get a constantly spinning fan, but beeping from the BIOS. If you still get only a couple of seconds of fan, it's the motherboard. Or possibly the fan - try a different one.

That said, your CPU is really going to struggle there - have you got a more powerful (700W+) you can borrow to test with?

STi8

I must say, I did wonder whether the 480w PSU would be up to the job, and tried to get the opinion of the supplier on that, but they didn't respond. Still, it's gone back now and we'll see what they have to say.