macmini 2012 HDMI shows no signal when waking-up from speep

Discussion in 'Mac mini' started by hjoon, May 12, 2013.

  1. hjoon macrumors newbie

    May 12, 2013
    My macmini is 2012 late version and I did all the latest updates including recent EFI and Thunderbolt updates.

    My macmini has a HDMI problem.
    If I set the sleeping timer to 1 minute and make both TV and macmini go to sleep automatically, both TV and macmini wake up well.
    But if I send it to manual sleep using the menu or keyboard, TV doesn't wake up and it shows only "no signal". Macmini itself wakes up and runs well and only TV doesn't wake up (very strange).
    This is 100% reproducible in my old LG TV and 20~30% happens in other TVs or monitors. Some times TV just get off while I am seeing a movie. I guess it could be related to heat.

    Once the "no signal" problem happens, rebooting or re-plugin of HDMI cable doesn't help. The only way is powering the macmini off and cooling off for more than 15 minutes (strange too).

    I got it to the Apple center and they tested and was not sure. They recommanded to use Apple genuine HDMI cable in stead of mine. Or I have to change the main board if I want.
    I purchased an Apple cable and also a minidp-HDMI cable as the macmini has a minidp port too.
    The Apple cable doesn't help at all but the minidp-HDMI cable works very well (I am using it now).

    Does anybody has the same problem?
    Or get me your opinion if this is a HW or SW problem.
    I guess it might be a HD4000 driver issue but I have to change the board before my warantee period is over if it's a HW problem.
  2. Woyzeck macrumors 6502

    Nov 2, 2012
    Occasionally my Mini does the same, but even on TB (over the DP cable). It shows a picture on the second screen (via HDMI) but my primarily one stays in sleeping mode. No signal.
  3. marc.garcia macrumors regular

    Jul 26, 2010
    I have a similar issue with mine. When I wake it up it displays the expected log-in screen, but after a few seconds it seems to switch off the video signal. Pluging the cable out and back in solves the problem, but it is very annoying. I don't want to go with a minidp because then I would need a separate cable for the audio right?

    this is strange because for a couple of months everything worked just fine, but after a while I'm having again this sort of problems... software update maybe?
  4. phrehdd macrumors 68040


    Oct 25, 2008
    I don't know what exactly causes this issue but you may want to check on EDID. There is a communication between device and TV that negotiates screen resolution. Somehow it may be possible that during this sleep the negotiation is lost and not renewed (so to speak).

    Just a thought - check out the XBMC and Plex media software player sites and raise the questions there. Since both software are used on Minis to TV, some may have ways to address this issue.
  5. geeji macrumors newbie

    Jul 24, 2012
    If the EDID is the problem, the solution is Gefen HDMI Detective Plus.

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