Power shuts down

tonydr58

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Jan 18, 2010
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My power supply shuts down immediately on startup. Disconnecting the 4 pin ATX12V aux connector gets the power supply running, but of course I cannot boot the CPU. This behavior in intermittent. The CPU will boot and run for weeks at a time, then stop. After a period of time disconnected, the cpu will boot and run normally again. There is no excessive heat or warning beeps. The supply is 450 Watts and the system has a single SATA 1GB drive and DVD RW, 4GB ram one case 80mm fan and regular CPU fan looks to use about 330 watts max. ASUS m3n78-em - AMD Phenom 9750 Is it power supply or mother board?
 
Solution
You may have a failing power supply. I recommend a good brand such as corsair, pc power and cooling, seasonic, antec, ocz or enermax. Lots of folks try to get by with some lightweight no name branded ps after spending a small fortune on their pc. Changing to a better brand is a good investment in the long run.
You may have a failing power supply. I recommend a good brand such as corsair, pc power and cooling, seasonic, antec, ocz or enermax. Lots of folks try to get by with some lightweight no name branded ps after spending a small fortune on their pc. Changing to a better brand is a good investment in the long run.
 
Solution

tonydr58

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Jan 18, 2010
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you need to have a lot of power for that equipment you have

A web PS calculator estimates 246 Watts for the setup I described. That leaves 200 watts to spare even if the estimate is off a bit.

The mobo is rated for
140 watts/onboard ATI HD5200/Phenonm X4,
CPU fan, 2 case fans (10w), 120 and 80mm,
1 SATA HDD (30W),
1 Sata DVR/RW (30W),
USB (20W)
2X2048MB DDR2 (30W).

270Watts.

either wey a correct functioning 450 Watt supply should be ok, I think.
Am i missing something? I am assuming the 140W mobo includes the CPU.

 

tonydr58

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Jan 18, 2010
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try unplug all the fan and see it work better to test PSU


Yes I removed everything but the mobo and still shuts down. If I remove the 4 Pin aux connector fromthe mobo, the PS runs ok.

I also tried removing the memory and got the power supply running, but obviously memory error.

 

tonydr58

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Jan 18, 2010
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it doesnt include the cpu, you need to have some watts for every core to run. times it by four.

+125 W according to the spec. so 395 watts on a 450W PS, closer than I want, but should run.

Is it typical behavior for the PS to simply shut down immediately if short on power?
 

tonydr58

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Jan 18, 2010
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New 450 watt power supply resolved the issue. The original was an "Extreme" and was replaced by a "Power Up". The new supply had better DC output ratings at 5 and 12 volts, but I feel like the original was defective. While it worked for about 6 weeks, it finally failed and could no longer operate a under load.

Thanks for everyone's input.