External monitor on laptop question - standby/sleep mode

Discussion in 'NZ Computing' started by Me, May 21, 2009.

  1. Me

    Me Guest

    I'm not sure if this is supposed to work differently, but if my laptop
    goes into sleep mode with external monitor (connected by VGA), the
    monitor doesn't go in to standby mode properly.
    Same monitor connected to deskptop is no problem.
    I can send a system message programmatically (ie WM_SYSCOMMAND,
    SC_MONITORPOWER) and that does put the monitor in standby, but after
    about 10 seconds it wakes up with a "no vga connected" message
    (generated by the monitor), same as when the laptop goes in to sleep mode.
    There's probably something fundamental I've missed. I can't see
    anything obvious in the graphics driver settings (the ATI interface is
    truly dreadful - I'd have made sure I got Nvidia if I knew), nor any
    obvious hardware setting on the laptop. I'd use DVI, but the damn
    laptop has HDMI out, and with HDMI -> DVI adapter, the graphics card
    won't output higher than about 1280x1050, yet works well with VGA - even
    seems to detect monitor native resolution no problem.
    Any suggestions?
    Me, May 21, 2009
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  2. Me

    PeeCee Guest

    I would think the VGA port on the Laptop goes into a high impedance no power
    state in sleep mode.
    (to save power)
    As such the monitor thinks the cable has been disconnected, hence tthe 'no
    VGA Connected' message.
    There 'may' be an option in the Monitors OSD to cancel this message.

    Otherwise I wouldn't think there is not a lot you can do apart from turning
    the external monitor off when you leave the room.

    PeeCee, May 22, 2009
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  3. Me

    Me Guest

    Thanks for that - I think you've summed it up accurately as "unfixable"
    via the laptop VGA port. There's no hardware setting in bios setup or
    using oem software hardware utilities to change it. I've updated graphic
    card driver, and will try again with the HDMI/DVI cable, as it doesn't
    make sense to me that 1080p is available via HDMI to a TV or screen with
    straight HDMI, but not via the adapter. Perhaps if I get that working,
    then the monitor will power down on DVI.
    There's no option for "power save on no vga" on the monitor OSD.
    Fortunately vga looks good - no shadowing/ghosting flickering etc., as
    otherwise I could be stuffed completely.
    Me, May 22, 2009
  4. HDMI/DVI adapters do not have active components AFAIK. They just
    convert the plug to the right physical format. The electronic signals
    are the same. A lot of graphics cards have specifications where they
    support higher video modes on the VGA output than on the DVI/HDMI
    output - I do not know why, but it appears to be a limitation in how
    the silicon works. My old Matrox G450 and G550 cards are like that -
    I ran into the problem when I was looking at using the DVI input on my
    Dell 2707WFP monitor instead of the VGA one. The G450 is happy to
    output 1920x1080 (and in fact up to 2048 x 1536) on the VGA port, but
    IIRC only 1600x1200 on the DVI output. I think it may have something
    to do with "dual-link" being required for the higher screen sizes on
    digital outputs.
    Stephen Worthington, May 22, 2009
  5. Me

    Me Guest

    Thanks Stephen,

    The HDMI out from the laptop supports HD (1920 x 1080) on "single link"
    mode, and more on "dual link" mode - according to the ATI website specs.
    But connected to the external monitor via HDMI -> DVI adapter, and it
    wouldn't do more than 1280 x xxx. I've yet to check since updating the
    The laptop (Toshiba) specs are vague and inaccurate. I'm using 1680 x
    1050 on a 22" monitor. That's not a listed resolution on the specs, but
    it works fine on VGA. In fact it's nearly perfect as the laptop LCD
    works at native 1280 x 800, with native 1680 x 1050 on the external LCD.
    Shut the lid on the laptop, and the #1 desktop shifts to the external
    - still at native resolution, - open it again, and I'm back to a
    extended desktop setup with #1 desktop as the laptop screen (good for
    tool palettes for graphic editing).
    Apart from the glitch with standby mode, it's odd how "we" ended up with
    a situation where there are three "control systems" looking after this -
    the hardware utilities on the laptop, the graphic card driver software,
    and windows (vista) "mobility centre". Analagous perhaps to having a car
    with a steering wheel, a joystick, and an autopilot, all working at the
    same time, yet all I want to do is drive to the shop to buy a loaf of
    bread. Perhaps macs have this sorted.
    Me, May 22, 2009
  6. I think that may mean that the HDMI/DVI converter you are using is
    only single link capable. It is not connecting the extra pins used
    for dual link.
    Stephen Worthington, May 22, 2009
  7. Me

    Me Guest

    Hmmm... - the cable that came with the monitor is DVI-D single link
    (9+9+1 pin). I shouldn't need (?) dual link for 1680 x 1050 for the
    monitor, or for 1920 x 1080 or less from the computer. The adapter
    looks like it's dual link (there seem to be connectors in the 6 "middle"
    link 2 positions).
    I've tried again with DVI connection after updating driver. I think the
    "bug" is the ATI driver. It will now allow me to force HD, but
    not at 16:10 ratio.
    I can connect my camera via HDMI to the monitor, and get HD (720p)
    "letterbox" without scaling. When the camera display powers down, the
    monitor goes in to power-save mode properly.
    Me, May 22, 2009
  8. From what I have heard, the ATI drivers have been pretty bad in the
    past, but supposedly there is an effort under way to fix that. I have
    Nvidia cards myself.
    Stephen Worthington, May 22, 2009
  9. Me

    Me Guest

    It's not so easy to connect a latop to an external screen without
    Laptop bios/setup has options to start with auto detect or internal LCD
    + external.
    Laptop utilities with function keys allow direct selection of which
    screen(s) are used, and whether desktop is extended or same on both.
    That system "remembers" what has been connected - I connected TV via S
    Video, and now the options for TV-extended or TV are on the (toshiba
    utilities) menu. Unfortunately that means that if I stuff up a setting,
    that stuffed up setting "sticks" when re-booting.
    On first receiving a signal, the external monitor auto-adjusts pixel
    clock and phase. If the wrong resolution setting is applied on startup,
    then corrected via the display driver, I get a partly blurry screen -
    and need to run an "auto adjust" to correct it.
    I use the external LCD for photography, and need it colour-calibrated
    via an ICC profile generated by software and a hardware colorimeter
    device. I need to be sure that the correct ICC profile is applied by
    the graphic card driver to the correct monitor when the OS loads. The
    perfect answer is a monitor calibrated with internal look up table, so
    needing no adjustment from the PC, but they are expensive.
    I think I've got it right now, but it's been a bit of a challenge.
    Next laptop I buy must have DVI out and an Nvidia card.
    I'm happy with the idea of replacing a desktop with a laptop for my
    needs. Bottleneck with my old system was sheer cpu grunt for raw file
    conversion using a raw file converter (Nikon) which updated/recompressed
    an embedded full size jpeg and thumbnail within the raw files on each
    editing step. It was "click and wait..." on a single core machine. A
    laptop was a bit of a gamble. I tried the software on my son's 1.6 ghz
    dual core "budget" machine, and once I'd enabled the dual cores (he'd
    disabled one to save power - doh) found that it was adequate - better
    than I expected. C2D in this machine works very well indeed, with 2
    separate disks, caching for that software set on the second disk, and
    the Nikon software utilising both cores fairly evenly. Now to go out and
    take some photos...
    Me, May 25, 2009
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