Acer AX1935 not recognizing PCIe video card: No option in BIOS to disable onboard video?

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CP
CP Member Posts: 2 New User

I recently purchased a low profile PCIe graphics card to help the Acer Desktop play some games. (Sapphire Radeon HD 7750)

 

The system does not POST. No monitor signal is passed either through the onboard VGA port or the PCIe DVI port.  There is no screen output at all if a PCIe video card is installed.  All fans and lights run when the CPU is switched on.

 

The option to disable onboard graphics is greyed out with the Acer BIOS.  It is permanently enabled.

 

Is there a workaround or fix to use PCIe video output?  The motherboard is identified as:

DIB75L-Lena

11073-1

48.3GW01.011

MADE IN CHINA

 

BIOS: 

AcerBIOSP01.A22.3 MB2012/05/21

American Megatrends Inc. P01-A2, 4/19/2012

 

Support Manual: 

https://support.acer.com/acerpanam/Manuals/acer/2012/ServiceGuides/SG_Aspire_X1935_Book_02172012.pdf

 

See also:

http://www.tomshardware.com/forum/296827-33-acer-aspire-m1641-problem

http://forums.pcpitstop.com/index.php?/topic/154440-computer-not-recognizing-pcie-video-card/

http://www.tomshardware.com/forum/364371-33-pcie-slot-acer-aspire-m3920

Answers

  • Travis-Acer
    Travis-Acer Acer Crew Posts: 681 Acer Crew
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    Unless you've upgraded the power supply in the unit, the 220 watt power supply that comes in this model is not enough to run the video card you mention.  The Sapphire Radeon HD 7750 requires a minimum of a 450 watt power supply according to the manufacturer. This would be the cause of the issue you are experiencing.  The onboard video will be automatically disabled when a fully powered graphics card is placed in the PCI-E x16 slot.

  • CP
    CP Member Posts: 2 New User
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    After trying the same card in three different modern machines with 400 and 650 watt power supplies with the same results, I returned the Sapphire Radeon HD 7750 video card for a replacement.  The replacement runs fine.  The Acer AX1935 normally runs about 35 watts at idle and 50-70 watts during load *without* the card.  I love this low energy consumption computer.  I have a watt meter, and the AX1935 uses 100 watts at maximum running BF3 with the card installed.

     

    There was a lot of documentation online that the Radeon HD 7750 card used around ~45-55 watts at maximum load, and PCIe x16 is designed for a maximum of 75 watts.  So the manufacturer of the Radeon HD 7750 surely wouldn't design a PCIe x16 card that uses more than 75 watts of power without an additional power input to the graphics card? Smiley Happy

     

    Summary: It was probably a bad card since all the other modern machines with 600 watt power supplies had the same POST issues, and the replacement has ran fine for several weeks to date.

     

    References:

    Kill-A-Watt measuring device: http://www.p3international.com/products/special/P4400/P4400-CE.html

    Power consumption of 7750 - http://www.guru3d.com/articles_pages/amd_radeon_hd_7750_and_7770_review,7.html

    Sapphire Radeon HD 7750 (MUST be a single slot low profile card to physically fit in this case):

    http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1159&pid=1658&psn=&lid=1&leg=0

     

    Specs from the AX1935 power supply unit sticker found in my case:

    Max Continuous: 220W

    DC Output:

    (+3.3V & +5V = 80W MAX.)

      +3.3V 16A

      +5V 16A

    +12V 16A (192W)

    -12V 0.3A (3.6W)

    +5Vsb 2A (10W) 

     

    Wikipedia on PCI Express Power: http://en.wikipedia.org/wiki/PCI_Express#Power

      75 W after configuration (+12V/5.5A & +3.3V/3A)  (66W + 9.9W = 75.9W)

  • Koogle
    Koogle Member Posts: 1 New User
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    Hi.

    I'm looking for the DIB75L-Lena MB manual you linked in your post. The link seems to be dead. Can you post a new link or send me the .pdf?

    Thx,

    Koogle

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