Have you tried booting the NUC with each of the monitors and swapping the cables between them? I'd be curious to know if one of the cables or that adapter could be causing the problem.
I am unable to swap since the monitors dont have the same connections. The FlexScan has only a DVI and VGA. And the issue arises only when the two monitors are connected at the same time during boot. They work if I boot with only one of the monitors connected at a time (doesn't matter which one), and after the boot is done I can reconnect whichever monitor was disconnected.
I must have misunderstood. I took your cable description to mean you had a mini-HDMI to HDMI cable and a mini-displayport to HDMI cable, with a DVI adapter on one.
What do you have the video memory set to in the BIOS?
What kind of mSATA drive do you have installed? I've found another thread with a very similar sounding problem that indicates with some mini-displayport to DVI configurations the system may not be detecting the mSATA. I know it sounds crazy but have a look here: Intel SSD 530 problem after OS Shutdown
A different cable might be worth a try.
The memory was set to 32MB, I changed it to 512MB just for the fun of it but it made no difference. I have 8GB of RAM in the NUC.
I actually have the 2.5" model of the NUC, so I am not currently using the mSATA port. Instead my main harddrive is a 2.5" Samsung EVO 840 250GB.
I also tried just now to add a delay in the BIOS when it engages the HDD, it was set to 0 seconds. I changed that to 5 seconds, now the INTEL NUC is actually displayed on both screens at startup but from there on out it does not progress further in the boot process. Super annoying right now.
I will have a look at the link you sent me, thanks.
Alright in order to rule out the cables I went out and bought a new set of cables for the DVI monitor.
Now I have a MiniHDMI to HDMI cable, from there it goes into a Philips HDMI to DVI converter.
It did not solve the problem.
I took a series of pics just to make it super obvious what is the problem.
Alright, sorry if it seems I am spamming, but there has been some development.
I decided to haul over another monitor and try the exact same setup (cable wise) but with a different monitor.
So I replaced the Eizo FlexScan S2231W with a ASUS VW228T, the cable hookup is exactly the same, Mini-HDMI to DVI etc.
Guess what? It worked fine! I rebooted about 4 times and it never failed, booted every-single-time.
So why is this? Well there are some differences between these two monitors. The ASUS is a native 1920x1080 60Hz monitor, just like my other EIZO Foris FS2333 (which I have connected to the DP port).
The FlexScan on the other hand has a native resolution of 1680x1050 it reports the refresh rates at fH 64.8kHZ and fV 60.1Hz while in Windows.
So is the NUC getting confused by having two monitors with different resolutions? Remember I can boot with the 1680x1050 monitor seperatly, but not together with another monitor it seems. My PC has worked fine with this setup for a year, no complaint. Why is the NUC different?
So, now what? I am not getting rid of my Flexscan. It is a perfectly fine monitor. There must be a way to solve this.
In short/TLDR: Temporaily replaced the FlexScan with a Asus VW228T and now the NUC boots with two screens connected. The only difference between the monitors if the different native resolution, 1680x1050 vs 1920x1080.
Fastson, I am sorry to hear that you are having this kind of problems on your NUC.
Please check the following URL for some important information when using dual display on these products. http://www.intel.com/support/motherboards/desktop/sb/CS-034199.htm
Something very important is that if you are using an HDMI monitor or HDTV that does not support a resolution of 1024x768, you cannot access the Intel® Visual BIOS setup when pressing the F2 key.
Well the problem is solved!
JasonHoffmans'ssuggestion about switching between the connections was the solution. After I bought another set of cables (see post #6) it was possible to switch between the monitors (since both cables were HDMI at the end that goes into the monitor, remember I have the DVI adapter already installed in the Flexscan). Anyway, for some reason this solved the problem.
The question is why the NUC behaves in this way? Connected one way but not the other? Very-very odd.
Perhaps it is something that Intel should look further into.
Thanks for helping me out Jason, the answer to the question was simple but perhaps not logical.
EDIT: I just posted as you answered Sylvia. The issue was solved earlier today. Thanks anyway. But please see my question above, it is a odd behavior IMO.
I'm glad it worked! Like you I have no idea why it would matter, but I've seen it before with the NUCs. They seem to be very sensitive to cabling when there are adapters involved.
I see the same issue here, and there is also an EIZO FlexScan S2231W involved (Mini HDMI to DVI connection). No chance to swap the cables however. Since the second monitor is a HP monitor with only VGA port, purchasing a second set of adapters and waste the first one is out of discussion.
Problem seems only to happen at cold boot.
Monitors wake from sleep, keyboard locks with all three LEDs (CAPS, SCROLL, NUM) on and thats it.
Tried disabling the watchdog along with some other config changes in Bios. This seemed to help with reboots, but cold boot still stuck.
The easiest workaround for now seems to switch off the VGA monitor before powering on the NUC.
Best greetings from Germany