LG 34UM95 Display Boot Issue

B1ueB1aze · Oct 7, 2014

Hello,

I have a LG 34UM95-P that I am using with my 6-core Late 2013 Mac Pro with AMD D500 GPU's over Thunderbolt. However, whenever I boot the Mac Pro, I don't get the Apple boot splash, or the FileVault password entry screens. The monitor just says that there is no input, and then enter it's power safe mode. However, when I enter my FileVault password when I think it's ready to be entered (as there is no image), OS X then boots fine, and the display detects an input, and works as usual.

I have attempted an SMC and PRAM reset. The PRAM reset did fix the issue on that boot, however after a reboot the issue came back. So, I did a second PRAM reset, however it didn't change anything that time and the issue persisted.

I do not have this issue over HDMI, just Thunderbolt.

Any help would be much appreciated.

Thank you in advance

B1ueB1aze · Oct 8, 2014

After trying out HDMI again, it appears the issue has now popped up with it. I am now having the same issue with HDMI and this monitor. HDMI was working fine every boot until I plugged it in using Thunderbolt. I have no clue how this is happening.

sirio76 · Oct 9, 2014

I've got similar issues a couple times back when the 34um95 was new(about 5 months ago). Don't know if the problem was that I was starting the nMP before turning the monitor on, but since I start to turn monitor on first I've never have the issue again.

B1ueB1aze · Oct 9, 2014

sirio76 said:
I've got similar issues a couple times back when the 34um95 was new(about 5 months ago). Don't know if the problem was that I was starting the nMP before turning the monitor on, but since I start to turn monitor on first I've never have the issue again.

I have the issue regardless of whether I turn the monitor on first or not. 99.99% of the time the monitor just doesn't get an input during the boot up process. This makes it impossible to select boot drives or allow multiple accounts to unlock the disk for FileVault; as there is no way to choose the account to use. I'm going to contact LG support as it seems like more of an issue with the monitor.

brentsg · Oct 9, 2014

I have several scenarios where my 2010 MP will end up with a black screen on this display, but with a working mouse curser overlayed.

Now I've also noticed instances where Steam in OSX will give me a gray screen with a working mouse cursor.. Ugh.

B1ueB1aze · Oct 9, 2014

I just contacted LG, and they're telling me that it's a problem with my Mac Pro. So, it looks like I'll have to contact Apple.

B1ueB1aze · Oct 9, 2014

Alright, well I just found out that if I hit the power button on the Mac Pro from a cold boot, and before the chimes sound, I turn the monitor on; it works fine. However, if I reboot that problem persists. So, it appears a workaround is to just always shutdown and cold boot instead of rebooting, and turn the monitor on right after pressing the Mac Pro power button. I hope Yosemite fixes this issue.

brentsg · Oct 9, 2014

B1ueB1aze said:
I just contacted LG, and they're telling me that it's a problem with my Mac Pro. So, it looks like I'll have to contact Apple.

There are an awful lot of issues with regard to this display. Even if LG is right, they should be helping to facilitate a fix. If people keep having these issues, it's not Mac Pros that people will stop purchasing.

B1ueB1aze · Oct 10, 2014

I just contacted AppleCare, and while even a senior advisor was unable to figure it out; they did a data capture and timing snoop and are sending it to engineering. I have a call back scheduled for Monday. I'll let you guys know what they say.

calaverasgrande · Oct 10, 2014

dang I was all set to buy one of these.
Anyone know if the UM94 has the same issue?

B1ueB1aze · Oct 11, 2014

calaverasgrande said:
dang I was all set to buy one of these.
Anyone know if the UM94 has the same issue?

I'm not sure if that monitor will have the same issue. However, I can say that the 34UM95 is fantastic once I've made it to the desktop and or login screen. The 21:9 aspect ratio is something I can never leave now lol. I hope though that Apple engineering can fix the issue. Especially since my Mac Pro is less then 2 weeks old. YMMV of with this monitor of course. I can only find a couple other people with this issue, so it seems like we're unlucky or something lol.

bias · Oct 11, 2014

I have (and love) this monitor on two workstations and they both have the same issue. It seems the monitor just needs extra time to realize it's receiving signal, through both HDMI and thunderbolt. I've just gotten used to giving them a bit more time on startup...

B1ueB1aze · Oct 11, 2014

bias said:
I have (and love) this monitor on two workstations and they both have the same issue. It seems the monitor just needs extra time to realize it's receiving signal, through both HDMI and thunderbolt. I've just gotten used to giving them a bit more time on startup...

That may be the case with yours, however with mine it never wakes up if I don't time it right. I've given them several minutes after starting the Mac, and they never wake up until I'm at my desktop or login screen.

B1ueB1aze · Oct 11, 2014

Just to update everyone, I actually got the callback form Apple today. And, their engineering team's fix was to do a PRAM reset with the monitor connected to HDMI, and just use it that way. It is working 100% now with HDMI, however it is limited to 50hz, which isn't really a huge difference from 60 anyways. I still do hope that Yosemite fixes this, but if not it is no longer a huge issue.

brentsg · Oct 12, 2014

Glad you can use your computer, but that's a lame work around. I'm growing tired of trying to get my 2010 MP to play nice with this display, and I'm considering moving on from OSX and retiring it. Everything is fine with my gaming PC, possibly soon to be everything PC.

MMcCraryNJ · Oct 12, 2014

That is a very lame workaround.

The way I see it, a lot of people have been using the nMP with this monitor with no issues whatsoever. So either your monitor or your computer has an issue. If you can live with the workaround, great, but it shouldn't be doing that at all.

B1ueB1aze · Oct 12, 2014

I'll wait and see if Yosemite works with it over Thunderbolt. If not, I think I might pick up a display port to Mini DisplayPort cable and try that out. Thunderbolt for displays is pretty new, and it looks like this is the only other monitor other then Apple's own that "supports" it.

100thMonkey · Oct 12, 2014

This is very disappointing, I was greatly looking forward to using that monitor, either that one or the 31mu95...the whole point is to use them over Thunderbolt and not HDMI

B1ueB1aze · Oct 12, 2014

100thMonkey said:
This is very disappointing, I was greatly looking forward to using that monitor, either that one or the 31mu95...the whole point is to use them over Thunderbolt and not HDMI

Indeed, I'm pretty disappointed about it not working as advertised. The AC support guy actually said he was surprised that LG is advertising it as Mac Pro compatible without Apple having added official support, or otherwise verifying functionality. LG or Apple really needs to release a software update, to add official support in OS X for Thunderbolt support, or LG should stop advertising it as Mac Pro compatible. As it appears at least over Thunderbolt, it is not.

HDMI seems to work again at least, other then that though, I was told that it was not officially supported by Apple, and there's not much more to do other then wait for an update, if it ever comes, to fix it. I do have to give some props to Apple though, as it's not officially supported, they really didn't even have to help me get it at least partially fixed at all.

calaverasgrande · Oct 12, 2014

Well LG doesnt have to do anything with Apple. Thunderbolt is an Intel thing not an Apple thing. That said it is pictured in some of LGs promo material with a NMP alongside it.
And it sure would be dandy if Apple, LG or Apple and LG got their act together on this one. There aren't a whole lot of TB monitors to choose from so you think it would be in Apple's best interest to support whatever TV monitors do exist.

MMcCraryNJ · Oct 12, 2014

Have you tried different TB ports on the Mac? Or try using the other TB port on the monitor? And, did your problem occur right out of the box, or was it working for awhile and then stopped?

There's gotta be something at fault here. I mean there are plenty of people on YouTube who do reviews on this monitor who have it connected to a nMP and I've not seen one mention this issue, nor have I noticed any forum member here chime in about it (there were at least several nMP owners in the thread for this monitor).

If your monitor is new and you're in your return window, I would RMA it with your retailer. If you get another one and the same issue happens, it could be a software or hardware issue with the nMP.

(Sorry if it seems like I'm being pushy, it just bothers me that someone spent upwards of $5000 for this setup and it's just not working as advertised. TB is a universal standard and I can't imagine that a software update could fix just this monitor in particular).

B1ueB1aze · Oct 12, 2014

MMcCraryNJ said:
Have you tried different TB ports on the Mac? Or try using the other TB port on the monitor? And, did your problem occur right out of the box, or was it working for awhile and then stopped?

There's gotta be something at fault here. I mean there are plenty of people on YouTube who do reviews on this monitor who have it connected to a nMP and I've not seen one mention this issue, nor have I noticed any forum member here chime in about it (there were at least several nMP owners in the thread for this monitor).

If your monitor is new and you're in your return window, I would RMA it with your retailer. If you get another one and the same issue happens, it could be a software or hardware issue with the nMP.

(Sorry if it seems like I'm being pushy, it just bothers me that someone spent upwards of $5000 for this setup and it's just not working as advertised. TB is a universal standard and I can't imagine that a software update could fix just this monitor in particular).

It was right when I connected it for the first time over Thunderbolt. I am also using the Apple Thunderbolt cable. I have used different ports on both the monitor and Mac, and they all result in the same issue. However, I'm typing this from it using Thunderbolt right now, as once I get to the desktop it works perfectly. It's just booting where it gives no image. I did discover something new today though, it appears the monitor actually does wake from it's power save mode briefly when the Mac is powered on, however it just says Thunderbolt in the top right corner which is the input it currently is using, while the rest of the display is black, and then it just reenters power save mode.

I have noticed in Apple's support documentation it says:

"You can connect up to:

Six Apple Thunderbolt Displays (27-inch), Apple LED Cinema Displays (27-inch), or third-party Mini DisplayPort displays."

And I noticed it says third-party Mini DisplayPort displays. It says nothing about third-party Thunderbolt displays. So, it looks like Thunderbolt may just be incompatible if it's not the Apple Thunderbolt display.

And, on top of that I did find one other person having the same issue here, https://discussions.apple.com/thread/6526031. Unfortunately, their thread has gone unanswered for over a month.

MMcCraryNJ · Oct 12, 2014

B1ueB1aze said:
It was right when I connected it for the first time over Thunderbolt. I am also using the Apple Thunderbolt cable. I have used different ports on both the monitor and Mac, and they all result in the same issue. However, I'm typing this from it using Thunderbolt right now, as once I get to the desktop it works perfectly. It's just booting where it gives no image. I did discover something new today though, it appears the monitor actually does wake from it's power save mode briefly when the Mac is powered on, however it just says Thunderbolt in the top right corner which is the input it currently is using, while the rest of the display is black, and then it just reenters power save mode.

I have noticed in Apple's support documentation it says:

"You can connect up to:

Six Apple Thunderbolt Displays (27-inch), Apple LED Cinema Displays (27-inch), or third-party Mini DisplayPort displays."

And I noticed it says third-party Mini DisplayPort displays. It says nothing about third-party Thunderbolt displays. So, it looks like Thunderbolt may just be incompatible if it's not the Apple Thunderbolt display.

And, on top of that I did find one other person having the same issue here, https://discussions.apple.com/thread/6526031. Unfortunately, their thread has gone unanswered for over a month.

It could have been that when Apple wrote the documentation, there was only one TB monitor out (their own). LG also has the new curved one out as well which is also TB.

I don't know. It's a weird issue for sure. I mean if it's just not compatible with an Apple computer, why make it TB at all? They were clearly targeting Mac users who focus on productivity/creative applications. And also, I've heard that it works perfectly on MacBook Pros via TB as well. You would think if this was a widespread issue, more people would complain about it.

I will say this...before I had to give it up, I had an old Samsung 22 inch monitor connected to my 2012 cMBP via DVI to miniDP cable into the TB port. And I also would not get the grey Apple boot screen, but it would turn on as soon as the password screen came up. So maybe that's just how it works?

B1ueB1aze · Oct 12, 2014

MMcCraryNJ said:
It could have been that when Apple wrote the documentation, there was only one TB monitor out (their own). LG also has the new curved one out as well which is also TB.

I don't know. It's a weird issue for sure. I mean if it's just not compatible with an Apple computer, why make it TB at all? They were clearly targeting Mac users who focus on productivity/creative applications. And also, I've heard that it works perfectly on MacBook Pros via TB as well. You would think if this was a widespread issue, more people would complain about it.

I will say this...before I had to give it up, I had an old Samsung 22 inch monitor connected to my 2012 cMBP via DVI to miniDP cable into the TB port. And I also would not get the grey Apple boot screen, but it would turn on as soon as the password screen came up. So maybe that's just how it works?

Maybe, but what's weird is that I can get it to display the boot just fine about 90 something percent of the time if I turn the monitor on right after pressing the Mac's power button and before the chimes sound as I've stated in an earlier post. So, I don't get it, it's like theres just that little bit of time for it to detect it correctly or something. I really have no idea what would be causing this issue.

B1ueB1aze · Oct 16, 2014

To update everyone, I updated my Mac Pro to Yosemite; however the issue is still occurring. So, Yosemite changed nothing about this issue. I also checked with someone else using this monitor and a 2013 Mac Pro connected via TB, and they said they do not have this issue, and the monitor works as it should. So, it looks like mine is an isolated issue, and no one has a clue how to fix it

LG 34UM95 Display Boot Issue

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