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View Full Version : Power short, maybe - Question


TheGreatSatan
03-22-2009, 05:24 PM
Someone I work with is putting his own pc together and it won't fire up. Originally he brought it to me and told me that it powers up, but nothing is on the screen. I took a look and his 12V line and an additional 4-pin molex connection on the board was not connected. Once all the right connections were made I fired it up again. It powers up (fans spin, etc), but nothing on the screen.

So, I tested the video card in another computer and it works fine. I reset the BIOS too. Could the mobo be shot from not having all the plugs connected the first time he turned it on?
Killa_Ape
03-22-2009, 06:58 PM
Is the processor getting power? I've had it where the connector wasn't in all the way and causing the same issue. Also if had power problems could check the connector if it's got power as well to the processor.
TheGreatSatan
03-23-2009, 07:44 PM
We plugged his processor into another computer and it works. Must be his board
mtekk
03-23-2009, 10:58 PM
That extra molex on the motherboard does not need to be plugged in unless you plan on overclocking the memory and/or chipsets (any board that requires it is too power hungry especially with modern 20+4 pin ATX and 4 or 8 pin +12V connectors).

The motherboard should not actually fry itself from not having the +12V connector connected, it just will not start up (no power to the voltage regulators that supply the CPU means the CPU never starts). In a worst case scenario the CPU would fry itself, somehow, but as you've tested that it can't be the case.

Try different memory, I've had a DOA stick keep a system from even posting.
TheGreatSatan
03-24-2009, 07:42 PM
Yeah, we thought of that too. The problem is that it's DDR3 and pricey/annoying to test
simon275
03-25-2009, 09:22 PM
I had this problem recently and my RAM was seated properly. Check that it is. As without working ram that is correctly seated a computer will power on but not post.
Luke122
03-26-2009, 05:41 PM
Have you attached a system speaker to the mobo? If not, add one and try to post again.. the beep codes (if any) should help you locate the problem. :)
p0Pe
03-26-2009, 05:56 PM
i had that problem once. it was beacuse the board had an old bios, and didnt reconize the cpu. put an old cpu in, updated bios and boom.

it was a E8400. and the board supported the "new 45nm cpu´s!"... they just forgot to update the bios on the models already shipped out, or take them back.