Compter wont POST on primary monitor - How to force it to?

SomeUserName · 22 Feb 2017

Motherboard is a B150M-C D3 using onboard video. No video cards installed. My primary monitor is 1, My secondary is 2 and #3 is my security Camera/overflow PC monitor.

Why when my computer does the POST test it does it on #2 and 3 instead of 1 and 2. It even POSTS on #3 when it is on security Camera mode making me switch over to another HDMI input to see POST. Monitor #1 remains blank. Once the POST is done then #3 turns off and the logon screen comes on #1 Main monitor like it should.

How do I force the computer to POST on Monitor 1 and 2 instead of 2 and 3 when powered up so I can see it instead having to turn off my security cameras to see my computer POST??

Main monitor on DVI
Decondary monitor on VGA
Thrid monitor = Security camera DVR on HDMI 1 and the computer is on HDMI 2. I like to leave it on the cameras instead of having to switch over to HDMI 2 at every reboot.

When powered on main monitor #1 should ***NEVER*** be blank.

Barman58 · 22 Feb 2017

Not sure but I would check that the MB is capable of powering all three monitors concurrently, most I've used will have more outputs than they can actually use at the same time. It's often a case that the outputs are limited to any two at one time. I know of some setups that use up to six monitors at once but these use multiple specialist cards to achieve this.

As for the monitor that presents the post information, I have found that a lot of Graphics cards and onboard chips have there own inbuilt order based on the actual output socket I use a GTX 750TI with a main screen on DVI secondary screen on HDMI. The card insists on defaulting to the HDMI port being classed as Monitor 1 and the DVI port being classed as Monitor 2 - I have to manually re-assign the numbers to get the system to boot on the correct monitor, but sometimes for no apparent reason this will re-set itself and need redoing

SomeUserName · 25 Feb 2017

I know that it can power all 3 as I sometimes will be working on the 1 & 2 and have Kodi playing a movie on #3. Done it numerous times.

THere is also a display port jack on the MB but I dont have any monitors that support DP.

May be a case of the display choosing it s own like you say then. Pretty crappy if so. There should be a way to make it permanent to user settings

Layback Bear · 25 Feb 2017

Just a thought.

Rearrange what cables going to what monitor, so it agrees with what your system likes.

In my opinion 3 monitors using a (i3-6100 Processor) without a video card is asking a bit to much.

Jack

johnhoh · 25 Feb 2017

This issue is controlled by the bios. I just looked at the manual for three different B150 boards made by MSI, ASUS, and Gigabyte and on none of them do they show an option as to which onboard port is the primary, which is kind of weird since there are four ports. The Asus manual actually does not even have the graphics field explained (only shows Advanced mode > advanced > onboard devices, under which I assume are the display options). Anyway, I suggest you go into your bios and check it out since I can't tell what options if any are there.

Even though they do not let you choose the primary, if you have only one monitor installed surely the board would detect it and use it as primary, and if so, your workaround to the problem means just unplugging the camera at boot up. When bios sees nothing plugged in that port, it will use some other port as the primary.

In any case, its possible that a newer version of the bios has different graphics options within it, so you might try that. And though you would probably have to stay on hold for an hour to get through, a call to Asus support is certainly warranted here. Or maybe a post to their online forum.

Another option is to buy your way out of the problem by using one or more adapters. Digital ports are compatible (DP, DVI, HDMI) so you could for instance plug your dvi monitor into an hdmi port by getting an adapter like this one.
Amazon.com: Generic GC2080 HDMI to DVI Adapter with Gold Plated Connector: Industrial & Scientific

Not sure if you are using the audio signal over hdmi or displayport but note that dvi does not carry audio. And I'm not clear that a displayport/hdmi adapter converts the audio either.But if you are only using video you have some options by using different adapters or cables. Also note that adapters like this can limit your ability to use nearby ports because they physically can get in the way. If so, you can just get a cable with dvi on one end and hdmi on the other, or displayport, whatever. My system has three dvi monitors and my board is a Z270 similar to your onboard video so my cables are dvi>hdmi, dvi>dvi, and one dvi>displayport.