I just bought a Athlon II x2 250 Regor from newegg in a combo with Gigabyte mobo MMA785GM-US2H. I got it with G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 and a case which came with a PSU X-Power 585. When I connect everything the memory and a monitor and the case fan and the case speaker and power LED. The power LED for the case is on, the power button on the case works and the case fan spins up. The heatsink fan does a "twitch" like it's going to spin and then stops and then 5 seconds later same thing. it does like a 1/32 turn to elaborate on the "twitch" and comes back to original position. Holding the power button for 10 seconds also doesn't turn the system off. I had a friend over who did a couple builds and we put the PSU in an old computer and it powered on no prob. He said he'd never seen anything like this before and couldn't figure it out. The speaker is silent to we can't tell if there is an error going on. I RMA'd the mobo and CPU and the new ones I got have the same result. I hope it's a dumb solution and I thank y'all in advance for reading and look forward to hearing your ideas. If there is any questions or more things you need to know I'll get back to you ASAP.

Welcome to the forum!

Did you update the Gigabyte mobo bios to at least version F2 prior to installing the 250?
Did you manually set the memory frequency, timings, and voltage in the bios?
Also could be a faulty stick, try one stick at a time (and in different dimms) to try to get it to post.
Is the HSF seated properly and what TIM did you use and how did you apply it?

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You have plugged in the 8 pin cpu lug havent you??

Sorry if I'm stating the obvious but sometimes the obvious gets over looked, especially if you are coming from and older system that didn't require the extra power plug.

If you don't know where to look the 8 pin socket is just behind the rear IO panel.

I'm glad you mention the obvious because the obvious is not obvious to me, in all seriousness. I wondered to death about this issue when I got this combo the first time. Yet the power supply that I have (if you follow the link in the original post you can check it out) does not have an 8 pin plug. There is a 6 pin and a 4 pin, the latter I used on the older system to check out the PSU. At one point I plugged in the 6 pin and the 4 pin into the 8 pin plug to try to see if that was the issue, this was with the first mobo and CPU that I RMA'd. Time for a dumb question. please take a look at the mobo I got (link in op) and tell me if it is necessary to have the 20 pin plus 4 pin plug and a 8 pin plug all in for it to work. If so then what kind of PSU can you recommend without breaking the bank that has that type of plugs?

This is a 100% new build. I can't get into the bios and have no means to try out the CPU, mobo, or memory on a older system right now (might change by next week) to update the mobo. I did try one stick at a time....same issue. HSF is seated well I believe, doesn't move and the TIM used was the one that came with the CPU and the HSF packaged together. Thanks for welcoming me to the forum, and this is an odd issue, so I appreciate you taking the time.

Hi again

Just wondering how you can physically plug a 4 pin and a 6 pin into an 8 pin socket.

The only six pin connector you would have would be the PCI-E connector for a graphics card and its not a good idea to use that in the cpu power socket.

Yes you should have the 20+4 connected to the mobo power connector.

If you don't have an eight pin connector then it should run off just the 4 pin but you won't be able to overclock is my understanding.

The pc will not boot without at least a 4pin connector plugged into the cpu power socket.

If you provide a budget then me or another member will reccomend a suitable psu for you.

hey magdary! thank for the reply(ies).

I was surprised it fit as well, but the PCI 6 pin fit into the 8 pin plug and the 4 pin fit into it too. I'm glad you mentioned the 'obvious' because I'm starting to believe that is what it is. At least that gives me something to try rather than the fury of empty questions I was hurling at myself. It's got me thinking about the PSU now and there is a picture of how the 12V 4 pin fits into the 8 pin plug here you just gotta scroll down a little. SO I'mma take the website's advice and find a PSU with an 12V 8 pin power connector. I'll holla with how it goes.

Ah I see, I thought u meant you had some how managed to get the 4 pin and 6 pin in at once which is what confused me as I couldn't see that being possible.

Depending on the wiring placement in the 6 pin putting it into the 8 pin socket could cause damage due to wrong voltages being applied but I'm not sure of this.

I would at least try it with the four pin correctly inserted and the 20+4 and see how it goes, if that doesn't work then you may need a new psu.