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Subject:
From:
Michael Eisenstadt <[log in to unmask]>
Reply To:
Personal Computer Hardware discussion List <[log in to unmask]>
Date:
Tue, 9 Feb 2010 17:09:12 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (103 lines)
Thanks, Russ, for your suggestions.

An obvious mistake of mine was to overlook the separate connector(s)
for the CPU which I need to attach. The mb has an 8 pin connector
labeled ATX_12V_2x4. The schematic for the 8 pin connector in the
manual identifies the 8 pins as follows:

1  GND  (Only for 2x4-pin 12V)
2  GND  (Only for 2x4-pin 12V)
3  GND
4  GND
5  +12V  (Only for 2x4-pin 12V)
6  +12V  (Only for 2x4-pin 12V)
7  +12V
8  +12V

The PSU has 2 2x4-pin connectors bundled together with 2 yellow
and 2 black wires each. Presumably the yellows are 12V and the blacks
are GND. Presumably the 2 connectors are meant to be seated in
the 8-pin mb connector side by side. They can only go in one way
and the (yellow) 12V and (black) GND wires correspond to the definitions
of the 8 pin connector (in the manual).

The PSU also has a 6-pin connector with 3 yellow and 3 black wires. Perhaps
that is to be used with other types of motherboards.

I do NOT understand what "Only for 2x4-pin 12V" means in the manual's
schematic as above.

I think it wise to wait for your recommendation about this.

As for the 2 other steps you outline, I believe I have installed the
CPU correctly and secured the mb to the case correctly with
insulated screws.

Thanks again.

Michael Eisenstadt
Austin Texas


> Hi Michael,
>
> To jump right to the end and answer your question, either the MB or CPU
> could be a problem. The CPU must execute BIOS instructions to be able to
> drive the speaker to provide the beeps.
>
> Now to some tips on what to look for.
>
> 1.) Make sure that ALL the motherboard power connectors are connected!
> Most motherboards these days require a separate 4 pin (ATX) or 8 pin
> (SLI) connector for CPU power in addition to the standard 20 oe 24 pin
> main power connector. It is a common mistake to forget to hook thses up.
> Sme dual CPU Xeon motherboard actually require TWO of these, making
> power supply selection difficult (only a few have this).
>
> 2.) Make sure the CPU is installed properly.
>
> 3.) Make sure there are no metal posts grounding out the motherboard to
> the case.
>
> Steps to help isolate the problem.
>
> 1.) Remove all peripherals except video, memory and CPU from the
> motherboard and try to power it on. If these works, then add them back
> one at a time until it fails again.
>
> 2.) Remove the MB from the chassis entirely and hook everything up while
> the MB is resting on a non-conductive surface to see if it will work.
>
> 3.) Try a different power supply. If it still doesn't work, then either
> the MB or CPU is likely defective.
>
> Russ Poffenberger
> [log in to unmask]
>
> On 2/9/2010 11:06 AM, Michael Eisenstadt wrote:
> > Hi all,
> >
> > I am trying to troubleshoot a new build. The details are:
> >
> > 500 watt Coolmaster PSU, Gigabyte GA-MA790GPT-UD3H motherboard,
> > 2Gig RAM DDR3 1300 Kingston, AMD Phenom II 3x 2.8Ghz CPU, Gigabyte
> > HSF installed, 3 v battery good (all new components all from Newegg),
there
> > is no beep code, nor does mb recognize mouse, keyboard, or monitor when
> > turned on. Mb supplies VGA. The case's power switch functions and the
> > Gigabyte HSF turns on. The case's speaker is attached to mb and was
working
> > with previous mb. I believe bad RAM has a beep code. Would a bad CPU
> > prevent the beep codes and the BIOS from loading? Or could this be a
> > defective mb?
> >
> >
>
>                          PCBUILD's List Owners:
>                       Bob Wright<[log in to unmask]>
>                         Mark Rode<[log in to unmask]>

                         PCBUILD's List Owners:
                      Bob Wright<[log in to unmask]>
                        Mark Rode<[log in to unmask]>

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