ASUS P8Z77M PRO computer wont start without pulling out and replacing cmos

jeanieb85

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Jun 27, 2012
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just bought brand new parts for a computer and got them put together but not working.
if you take out the cmos and put it back in then turn the power back on at the wall then you press the power on button on the case and it starts up fine and loads into windows 7. and u can play and go on the internet, everything.. until you press reset or shut down

then when you try to press the power on button nothing happens, no flicking fans, lights, until you pull the cmos back out again.

have downloaded and installed the current BIOS update 1301
ran an asus pc diagnostic and all components and tests got a PASS.

took out the cmos and tried 2 others from different computers, tried different power points in the house to make sure it wasnt any weird power surge problems going on..

wats left to do??

ASUS P8Z77M - pro MB
550w extreme power plus coolermaster
Western Digital Green 1TB HD
intel i5 3450
Asus gtx 560 ti direct cu 11 oc 1gb




xxxx Mrs B
 

VR2012

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Jul 4, 2012
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We had the same problem. If you touch the internal powerconnector (24-pins connector) at the same time as you power on the machine, it will work without resetting the CMOS. This is a hardware-error, you should get it replaced.
 

denisns

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Oct 7, 2012
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Same problem here. My pc won't start unless I clear the CMOS every time. Have the same mobo but different parts and OS.

Haven't found a solution and have no idea whatsoever.

LEt me know if find out.

Thanks

 

denisns

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Oct 7, 2012
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Are u sure? Couldn't it be the bios? Im doing research on the subject to try and find a solution, and even called an expert to help me. He will be examining my computer this tuesday (oct 09) and I hope he can solve it.

This is the first time I build a computer and I'm very excited it works, even with this issue and some other. Once I figure out how to solve everything I'll post in here.

Thanks
 

Blodoffer

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Oct 19, 2012
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I'm excited to hear what was the verdict. I have flashed the latest BIOS and still the problem persists.
 

denisns

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Oct 7, 2012
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Still not booting. I've flashed BIOS version 1504, but that didn't work. There is a newer release, version 1616, which I haven't tried.

Got a reply from Asus support blaming my PSU. It's indeed a cheap and unknown brand. So I decide to buy a good PSU and chose the Corsair HX650. Now I'm just waiting for it to arrive and test it. Will post the results, but it will take a couple of weeks, as it is still on its way from Florida to Sao Paulo, Brazil.

Meanwhile i'm clearing CMOS every boot and entertaining myself installing Windows 7 and Ubuntu side by side for dual boot and trying to make HDMI sound work, which has been really hard to acomplish so far.

What's you PSU model and maker?
 

Blodoffer

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Oct 19, 2012
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I have (SST-ST50F-ES) Silverstone 500W, Strider Essential which is basically on the suggested PSU list, because the 400W version is. So at least in my case PSU probably isn't causing the problem. PS. I have flashed 1616 with no luck.
 

Adrian Brough

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Jun 6, 2013
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I have 3 decent power supplies, a Zalman, OCZ and a brand new Seasonic. They all work in my other PC's but on my Asus P8Z77-M Pro only the Zalman will allow the mobo to power on regularly. The other two require me to clear the BIOS each reboot. WTF is going on? My Zalman doesn't have enough wattage to run my system at full load otherwise I'd be happy...