Help! Power Supply or Motherboard Problem!

cameronkwang

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Nov 15, 2012
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Hello All,

This is my first post on Tom's Hardware as I have no where else to turn for tech support. My package from Newegg arrived last night and I began to assemble the new computer. All parts were new, unused.

Here are the specs.

MSI Z77A-G45 LGA 1155 Intel Z77
COOLER MASTER GX Series RS750-ACAAD3-US 750W ATX12V
Patriot Intel Extreme Master, Limited Edition 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 15000)
Seagate Barracuda Green ST1000DL002 1TB 5900 RPM SATA
Intel Core i5-3550 Ivy Bridge 3.3GHz (3.7GHz Turbo) LGA 1155 77W
Nvidia GTX 285
Corsair Force Series 3 CSSD-F60GB3A-BK 2.5" 60GB SATA III

After assembling everything, I flipped the switch and pressed the power button. The machine whirled to life before powering down. No beeps, no video, nothing. So, I unplugged the graphics card and tried it again. Still no luck. I don't think it's the CPU after I realigned it, the thermal paste seems to be adhering to the CPU and the heat sink. I've never had any problems with mobos, so maybe it's my time to get a DOA. But the machine is fully operational before it shuts down, which it then restarts a couple of seconds later. Any help will be greatly appreciated, and I will post additional information as needed.

Thank you in advance.
 
You can get power supply testers to find out if that is bad. If it isn't the psu, its probably a bad motherboard. Did you triple check that all of the connections are made and tight? It could be shorted somewhere too. Try reassembling it outside the case. Try reseating the memory and any expansion cards you have too.
 

flexxar

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Oct 6, 2012
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Hard to say without knowing how far it got into bootup. Did it post? Did you see anything on the screen? How much hermal paste are you using? More than 1-2 grains of rice worth is bad.

It sounds like an overheating or power problem because it does a hard shut off. Bad motherboards like to display errors/make noises/system freeze so I hesitate to blame it.
 

flexxar

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Oct 6, 2012
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I would disconnect everything and start at the bare minimum. Connect the power connectors to the motherboard only. There should be 2. Remove all cards from the motherbard except cpu+heatsink and one stck of ram in slot 1. From the motherboard, connect only the required cable for your power button. Try to power it up. If it doesn't power down, connect devices up one at a time until you find the component that is stopping it from booting.
 

johnh83

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Nov 8, 2012
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Hi, cameronkwang. Like others have suggested, I would start with the bare minimum components i.e. speaker and CPU and see what happens at each stage of adding another component. It could be you've got a short circuit somewhere, so try taking the motherboard out of the case to test whether it at least works in isolation.
 

Majestic One

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May 1, 2011
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did you check to see if the Motherboard jumper is set to ship or use?
seems the most likely situation here.
there is a jumper on your MoBo (motherboard) that has 3 pins. shipped it is shorted and to use you must put the jumper on the OTHER 2 pins. It is usually a red jumper in the bottom right area of your MoBo as you look at it (CPU facing you)
 

twystedfyre

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Sep 27, 2012
18
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10,510
buddy i have the same mobo and cpu lol and had the same problem! no post no bios, just a flicker of life then it was off

after calming down from the new heart attack i had i realized i was missing a power connection to the mobo :p

there should be two, the one i overlooked at first is top left of the cpu, an 8 pin i believe... and the usual 20/22/24 (not sure) power connection to the right of the RAM sticks... hope this is your problem and it works!