Booting without monitor (cable) attached…

I tried to boot my Skylake setup without a monitor (cable) attached and it failed, up until the moment that I connect the monitor cable. It didn’t even (try to) load the boot loader from the M2 SSD. What I noticed was a flashing cursor at the top left corner, and only then did it load the boot loader from the M2 SSD. This is a serious BIOS bug.

Three questions:

1.) Can you boot (your Skylake setup) without a monitor attached?

2.) If yes, is that with an NVIDIA (or AMD) dGPU or the IGPU?

3.) Do you happen to know a work around for this problem?

Edit: It boots up with the monitor cable attached, even if the monitor is switched off – the BIOS may want to read the EDID and use the power from the DVI cable.

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17 thoughts on “Booting without monitor (cable) attached…

  1. i7-6700HQ (HD530) + HM170 notebook, el cap 10.11.6, using clover:
    1) Yes, also this is the only way i can boot. Attaching HDMI cable during boot results in black screen/reboot.
    2) With IGPU. NVIDIA gpu is disabled via ssdt
    3) Unfortunally not.

    • Hi Marco,

      Thanks.

      1.) Is that a black screen with a cursor?

      If yes. Press enter and note the flashing background – as if you are using a secondary desktop – then enter your password. That leads here to the desktop.

  2. Hey Pike, this sounds like an issue I saw many years ago when I was in support at one of the major computer manufacturers. Out of curiosity, what do you have your boot order set as in the BIOS, and what peripherals do you have attached to the system?

    • I only use the IGPU and thus that is set as primary output device. I also tried booting with the auto setting, with a normal SSD, and no USB devices like the keyboard attached, but that did not change anything. I also tried booting with VGA and HDMI monitors, instead of the DVI monitor that I use normally, but without luck. I even tried to boot from a USB flashdrive, which works perfectly fine with the DVI monitor, but I don’t get anything without first plugging in a monitor cable.

      Please note that I use a legacy boot method rather than UEFI.

  3. Before I added my NVidia GPU (so, running IGPU only), my GA-Z170-HD3P would refuse to even POST without a video device attached. I haven’t yet tried with the NVidia GPU.

  4. i7-6820HK (HD530) + Nvidia 980m GTX in optimus configuration + HM170 notebook
    1.) Yes i can boot without an external monitor attached (tested on El Capitan and Sierra)

    2.) If i do not plug any external monitor the Intel HD530 will load. If i plug an external Monitor (HDMI out) The dGPU controls the external display.

  5. I could not boot iGPU or NVidia without a monitor connected until I set “Fullscreen Logo Show” to Enabled. This is on a GA-Z170X-Gaming 7 (BIOS version F20) with i7-6700K. I found that suggestion at http://forum.giga-byte.co.uk/index.php?topic=17110

    Well, I tried it a few times, but now it stops booting again unless the monitor is connected. Maybe I need to reset BIOS options to defaults again. Maybe it would be more stable if I wasn’t using XMP Profile (3200 Mhz) RAM, or overclocking to 4.6 GHz.

    • Thank you. I’ll try this later today. May even help Gigabyte to solve this puzzle.

      Edit: Nope. Too bad. Does not work here.

      One other observation. This is interesting. USB appears to be switched off, after a certain amount of seconds. The same thing happens when I try to wake the PC after sleep.

  6. Hi Piker, using a Desktop (1912) HD530… (i5-6600)

    I can boot without any Display attached, desktop works, i can rename files etc…
    I do it just blindly…
    I can even send my PC to sleep with the hotkey combo…

    But if i attach the screen, it stays black, so i can still see nothing 🙂

    Need to patch GraphicsDevicePolicy for hotplugging, and check again if i can attach screen 🙂

    But the PC itself boots to Desktop without any issues without a screen…

    Cheers 🙂

      • Some Other its a Shuttle SH170R6… So there is some noname crap, but i’ve modifyed the bios (updated gop drivers etc… unlocked some things like MSR…)

        Tryed with disabled GraphicsDevicePolicy now, same… i can boot fine, but if i try to connect the display after boot i get no output….

      • Please define “no output”; is that a black screen with or without the cursor on it?

        Edit: Is that with or without dGPU?

        Also. I rather use some “crap no name” motherboard that works than a so called top-of-the-notch-brand that fails time after time.

      • Black screen like its off. (IGPU only, HD530)
        Its a apple cinema hd display, so there are no messages such as “no signal” on normal screen…

        So i boot without any screen attached, i can edit files on the desktop (rename etc…) , but if i connect the screen, its off like “no signal”… without any cursor…
        Need to reboot with attached screen to get everything working…

        It is indeed a crap noname board,
        the boot to “Press F2 to enter Bios” takes 5s
        if you are in the bios you have only some options like:
        Quiet Boot / Fastboot / Boot Order HDD/USB/CD / Save & Exit / Exit without save…
        Thats almost all options…
        So you are forced to modify bios, to get all options from any “named” board back…

        And i dont need to say anthing about bios updates from shuttle or crappy acpi tables…

        This board is crap! Its just working after some bios edits.

        Here are the complete specs:
        Display: Apple Cinema HD 24″
        CPU: i5-6600
        GPU: HD530
        HDD: Intel SSD600 (NVMe) 128GB M.2
        RAM: 32GB DDR4
        LAN: Intel I218-LM
        Shuttle SH170R6

        I hope i answered all your questions 🙂
        Cheers 🙂

  7. My Asus Z170M-Plus boots perfectly fine without monitor attached, both with iGPU = Primary and dGPU=Primary as well as CSM on/off.
    Didn’t check without dGPU (R9 280 most times) though.

    • Ok so you are using an Asus motherboard. Well. The problem may actually be limited to Gigabyte (again) or some BIOS version for the bards, but this has yet to be confirmed. Thanks!

  8. Hello Pike. I’m on a Gigabyte board and after update to Sierra 12.3 I wanted to boot as I did with El Capitan: No cable from iGPU, just my AMD 380X. Black screen until after boot etc.

    But it never came on. The screen stayed black. Attaching a HDMI to the iGPU afterwards made no effect, there was nothing there.

    I don’t know if my problem is the same as the one you’re describing here, but I fixed it. I made several changes, and I’m not sure which one that made it work (or if it just fixed itself by coincidence). These are the settings I can think of:

    In BIOS:
    iGPU set at Primary
    Show Boot Logo (Enabled)
    Internal Graphics (Enabled) (changed from value Automatic)
    DVM Preallo (64 MB)

    In Clover:
    Inject ATI: True. Framebuffer = Lagotto
    Inject Intel: True. Regular platformID value for 530.
    Applied your AAPL,GfxYTile patch plus patch from Multibeast.

    That’s it. I think it was the bios settings that made it work.

    Maybe the issue wasn’t even solved by the new settings, but if it is, I’m glad if I have been of help. Many thanks for your patches and work! Have a great day.

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