Q: Installed Mavericks, now HDMI Monitor is black. Any ideas?

I am having a very similar problem.

I have the 15" Macbook Pro Retina and its hooked up with a Viewsonic 27" LED monitor via HDMI. From time to time my display will turn black/off and its random and frustrating.

There's no indication that anything is causing this, I have only a keyboard & mouse plugged into my USB ports and the monitor plugged into the HDMI port. I rarely use the macbook without this second display and always have the lid closed...so I've not really experienced this problem when I use the laptop without an external display.

Chris Powers

I just installed Maverick onto my Macbook Pro, and now my "Displays" setting can not detect my Apple Cinema Display which I have been using for 3 years with my laptop.  Now I have to use my laptop's screen while my Cinema Display sits idly by as an expensive paper weight on my desk.

What happened, Apple?  This Maverick update sure looks like a dud...actually worse...a massive bug dressed up in an upgrade's clothing.

I have a similar problem. Sep-2010 MacBook Pro and Sony TV.

Since installation of Mavericks the thunderbolt/HDMI connection which I have in the past used to mirror my display to the TV no longer works. The MacBook doesn't see the TV and vice versa (the TV screen stays blank).

If these glitches continue to mount up (I have other problems with iOS7 on my phone), I will be moving on. I begin to form the impression that Apple is losing its way.

Same with me. Been forced to use an old Gateway vidicon-boat-anchor of a display. Just sad...

Same problem here with 15" MBP (early 2011) and Samsung HDTV via Thunderbolt/HDMI adapter (3rd party).  TV sees the connection as the onscreen input (HDMI 4) is highlghted but the computer won't detect the TV.  Is this a conspiracy to force us all to buy Apple TV?

Same here.

One of my TVs stays blank after plugging in the HDMI/Thunderbold (13" MacBook Pro 2011). Preferences seems to detect the TV, but it does not work.

I hope Apple fixes all these bugs soon.

I have the same problem .. Imac 27' ... connection to the TV using an HDMI cable is not working anymore after Maverick ...  How is possbile to have such a BIG bug!?!!?

I used a HDMI->DVI adapter with my Dell 24" monitor/Retina display MBP. This was working before Mavericks update (with mountain lion). It appears to not be detecting my monitor at all now. How frustrating.

As an update. The HDMI output does work with my televisions so I can only guess they've made these outputs only compatable with HTPC supported devices which most computer monitors do not support. I do hope this is temporary.

I have a similar problem. MacBook Pro (2013) and Sharp TV.

Since installation of Mavericks HDMI connection which I have in the past used to mirror my display to the TV no longer works. The MacBook doesn't see the TV and vice versa (the TV screen stays blank).

Yep, I'm experiencing the same problem. I'm using a thunderbolt to hdmi cord (3rd party) to connect my 13" MacBook Pro to my Vizio 32" TV, and as of this morning the my MacBook Pro's display would not appear on my TV. There was no option for it in display preferences on my Mac, nor did the TV respond at all. It was working fine on Mountain Lion, and now that I have upgraded to Mavericks it isn't working for me either. At least this is a common problem and not one of those pesky individual ones. Hopefully Apple releases some sort of update soon that will fix this, seems like it's been well over a week that MacBook Pro users have had this problem.

Add me to the list.  15" MacBook Pro Retina Display using HDMI cord (no adapters) has no display on LG TV.  Sitting in a hotel and was planning to watch a movie which I did many times on this MacBook at this same hotel using Mountain Lion.  How did Mavericks get released with such an obvious bug????!!!!

yup .. me too .. macbook pro mid 2010 - mitsubishi tv using rocketfish adapter to HDMI -- had no no no trouble for years.

since mavericks, it doesn't show ... HOWEVER, If I reboot my mac with it plugged in & the tv on that input, it does come up ... but if i unplug and plug back in ... i'm back out.

there should be a command (at the least) that you can call (like from terminal) to force a display refresh.

Thx, traceywashere. I am going to try that out.