3 Beeps on startup, post code 20

December 11, 2012 at 15:48:32
Specs: Windows 7, Intel i7 / Corsair Vengeance 16GB

When I try to start my computer after being completely turned off, the the computer beeps 3 times and my motherboard gives post code 20. Also, the fans are louder than normal when this happens. If i then turn off all power to the computer, wait for the lights on the motherboard to go off, turn the power back on and try again, the computer will then turn on without a problem. I have read that the 3 beeps and post code 20 are caused by a memory problem, but I have made sure that the RAM is fully in place and following the steps I listed above seems to fix the problem until I turn the computer off again. Also, this only happens after the computer is fully turned off, not on a reboot.

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#1
December 11, 2012 at 17:25:27

You didn't provide the make/model of your motherboard or which BIOS it uses. If it's an AMI BIOS, 3 beeps means bad RAM. Did you test the RAM with memtest86 or memtest86+?

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#2
December 11, 2012 at 17:33:15

Suggestions would include cleaning the ram contacts with a soft pencil eraser,
removing/re-inserting the ram 6 to 10 times to ensure clean contact in the ram slots,
testing bootup from cold with only one stick of ram,
Run ram diagnostic ( Memtest86) from a bootable floppy or CD to test your ram for errors.
Does your system have a reset switch? or if you press/hold the power switch until it shuts down will it then boot up?
Did you build the system or is it a brand-name OEM system?
What make/model powersupply does it have and what are the amp ratings on each voltage rail.? This info is on a label on the powersupply.

Goin' Fishin' (Some day)


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#3
December 11, 2012 at 19:06:32

Another thing to try (quick, but i'm not too hopeful) is to remove the power plug (and battery if it is a laptop). Hold the power off/on button in for about 20 seconds then try it.

Always pop back and let us know the outcome - thanks


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#4
December 11, 2012 at 22:02:30

My motherboard is the Intel BOXDZ77GA-70K. I just ran a test with memtest86+, and it found no errors.

It is a system that I built. I will try cleaning the RAM contacts if I have time tomorrow, and also take a look at the label on the power supply.


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#5
December 12, 2012 at 05:53:48

According to the manual, 3 beeps indicates a memory problem. How many hours did you run memtest? Did you manually configure the memory settings in the BIOS or just accept the default/auto settings?

http://downloadmirror.intel.com/209...


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#6
December 12, 2012 at 13:27:06

Memtest86+ ran for about an hour. I just left the default settings in the BIOS, but is there something that I should have changed? By the way, my RAM is Corsair Vengeance 16GB.

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#7
December 12, 2012 at 21:20:10

Try it with just one stick of ram, see how it boots, if it does the same thing, turn it off, yank that single stick out and put in a different single stick, turn it on and see if that changes anything. 16gs of ram is a lot to test in one hour and sometimes it takes several passes to detect an error. Most fail the test quickly, but there those pain the rear ones that take days to fail, but ultimately do. The other possible is as every one mentions the power supply. I have a power supply tester and even those can say the power supply is fine, but when I replaced it the problem resolved. Some things can be icky.

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#8
December 18, 2012 at 16:05:58

Using only one of either of the two sticks of RAM causes the computer to turn on fine.

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#9
December 18, 2012 at 16:34:01

I suppose it could be oxide on the edge connectors causing it to play up. Clean the edge connectors with a pencil eraser then insert the sticks in and out a few times (both sockets, to clear any oxide off the connectors themselves). See if that helps.

Always pop back and let us know the outcome - thanks


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#10
January 19, 2013 at 09:29:36

I tried cleaning the connectors with a pencil eraser, but it doesn't seem to help. Is there anything else I can try, or do I need to buy new RAM?

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#11
January 27, 2013 at 14:57:13

"Using only one of either of the two sticks of RAM causes the computer to turn on fine"

Does it matter which socket they are in?

Always pop back and let us know the outcome - thanks


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