LG 55LH5750 TV HDMI issue with Mac Mini

Interesting issue, if the Mac Mini is rebooted and the LG TV is powered off, when the TV is powered on the LG will not be recognized by the Mac Mini. Mac says "Unknown Display " and the LG says No Signal. If you Hot Plug the HDMI cable, Mac will still not HDMI sync with the TV. Only solution is to reboot the Mac Mini with the TV powered on. Same is true if using HDMI or and HDMI to Mini Displayport cables or a Mini Displayport to HDMI Active adapter. The Mac Mini just does not like the LG TV's. This problem does not exist in our environment on Samsung, Sharp, NEC, or Sony all of different age and models. This issue seems to be EXCLUSIVE to the LG TV's. The LG works fine in this scenario with my MacBook Pro, just not the Mac Mini


Any ideas why the Mac Mini and LG cannot successfully HDMI handshake after a reboot if the TV was turned off? Also note the Mac Mini will not initially recognize the LG when first plugged in, that required a reboot also.

Mac mini, macOS Sierra (10.12.1)

Posted on Dec 5, 2016 12:28 PM

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2 replies

Dec 5, 2016 1:05 PM in response to BDAqua

Nothing significant other than typical image settings, using HDMI1 on the LG, issue exists on HDMI2 also. Strange that works great if TV was on durning boot but if TV is off, the Mac never sees the TV and TV says no signal from the Mac. But a Hot Plug of the HDMI cable should force an HDMI handshake. Strange EDID or HDMI Handshake issue for the Mac Mini.

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LG 55LH5750 TV HDMI issue with Mac Mini

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