VERY STRANGE - Help !!

[xenzon]

Hello, ill try and be brief & post a real hello in the welcome section asap!

Right, bought a new Mobo CPU RAM combo.

Core i5 760 - MSI P55-GD65 - GSkill Ripjaws DDR3.

Now, the problem lies with the CPU. When I press the power button the computer comes on and then goes off after 0.5 seconds. Then after 5 seconds, it comes back on and then off again within 0.5 seconds. It will do this continuously untill I turn the power off again.

I've narrowed it down to the CPU, but still unsure. Heres why...

The combo works perfectly with a different i5 760. So the mobo,psu,ram,hdd's are fine. It all also works with an i5 540 cpu.

Also the 'dudd' i5-760 won't work in a ASUS P7P55D EVO, but the other i5-760 & i5-540 work fine.

BUT... The 'dudd' i5-760 works fine in the guys mobo who I bought it off. Took it back to him and he showed it me working perfectly.

So bludy stumped!

I've built quite a few computers before and never had this trouble. I want to get it going as its a massive increase over my current Phenom II 920.

Please can anyone help?

P.S. Ive tried clearing CMOS/Battery. A new battery. Diff PSU/RAM. Diff HDD's including a brand new unused HDD.

Mark.

 

[jph1589]

Hello, ill try and be brief & post a real hello in the welcome section asap!

Right, bought a new Mobo CPU RAM combo.

Core i5 760 - MSI P55-GD65 - GSkill Ripjaws DDR3.

Now, the problem lies with the CPU. When I press the power button the computer comes on and then goes off after 0.5 seconds. Then after 5 seconds, it comes back on and then off again within 0.5 seconds. It will do this continuously untill I turn the power off again.

I've narrowed it down to the CPU, but still unsure. Heres why...

The combo works perfectly with a different i5 760. So the mobo,psu,ram,hdd's are fine. It all also works with an i5 540 cpu.

Also the 'dudd' i5-760 won't work in a ASUS P7P55D EVO, but the other i5-760 & i5-540 work fine.

BUT... The 'dudd' i5-760 works fine in the guys mobo who I bought it off. Took it back to him and he showed it me working perfectly.

So bludy stumped!

I've built quite a few computers before and never had this trouble. I want to get it going as its a massive increase over my current Phenom II 920.

Please can anyone help?

P.S. Ive tried clearing CMOS/Battery. A new battery. Diff PSU/RAM. Diff HDD's including a brand new unused HDD.

Mark.

I haven't posted here for a while, but my gut tells me this is a voltage issue. I read something about the early versions of that cpu requiring more voltage (1.225v is what I saw). The later versions only needed 1.125v. So maybe it is one of the older ones and the guy you bought it from already had the cpu voltage increased in the bios so it was happy.

That doesn't explain why your bios wouldn't just set the voltage correctly but it really sounds like the way it would act if the cpu wasn't getting enough volts. So try posting it up with another cpu to increase the voltage in the bios and then put in the 760 and give that a go.

That is just a WAG!

 

[xenzon]

cheers mate, im going to try and re-flash the bios with the working i5-760.

see if i can set the cpu voltage abit higher then try my CPU.

ill post back later. thank god for my ancient laptop.

 

[Grizzly]

In case this doesn't work you can use one of your other CPU's to update the motherboard BIOS, I know mine added support for newer CPU's after I bought it.

 

[xenzon]

In case this doesn't work you can use one of your other CPU's to update the motherboard BIOS, I know mine added support for newer CPU's after I bought it.

Didn't work. Updated BIOS to newest. Set higher voltages, set lower voltages, used Auto on all voltages. Tried Last best used settings.

Tried everything. New Mobo or CPU im guessing :-( :-(

 

[Grizzly]

If you bought 'em both off of the same guy I'm sure he'll test it and realise the problem himself when you're returning the stuff. As opposed to him refusing because he can prove it works.

 

[xenzon]

Boards and cpu from diff sellers. But i have given up. I just going to buy the cpu sellers board off him as i know it works because ive seen it working.

Ahwell. So bloody strange! What a mystery.

 

[jph1589]

Boards and cpu from diff sellers. But i have given up. I just going to buy the cpu sellers board off him as i know it works because ive seen it working.

Ahwell. So bloody strange! What a mystery.

When you go to see the seller. Ask him to run cpuz on the dudd cpu in his motherboard so you can compare it to your working cpu's cpuz. Maybe that will give you some idea of what is going on.

 

[Miikkii]

Try re-seating the RAM, make sure the motherboard is screwed in correctly as it may not be grounding properly (to the case). Make sure all power connectors are connected properly.If you are using a aftermarket heatsink, try using the stock Intel one.

Look for any signs of burns or black on the CPU's base or the sockets pins.

 

[xenzon]

Nothing worked. absolutely pointless that MSI board was.

I've gone ahead now and bought the sellers Gigabyte P55-UD6 board. And damn it's a stonkingly good board.

Everything now works perfectly fine and the 'dudd' i5-760 is cruising along nicely at 4.0Ghz @ 1.3v Core and ram at 1800mhz @ 1.5v.

Everything perfect. Loving my new system.

Thank you to all who helped and left comments

All the best, Mark.