I would try another DP cable and or a different port on the GPU.
Nope. Same issue. I am using a DP to HDMI adapter. Also, I swapped the monitors so they were in different ports, but the same monitor is having the issue. Therefore, I would surmise it isn't the ports, otherwise the opposite monitor should be having the issue.
Sounds like its the monitor then? If you changed ports and its still doing it?
I have the same issue
I have 2D FHD LG TV connected to HDMI as Monitor 2 (set on primary monitor) and LG E2350 connected to DP with DP to HDMI cable 2m as Monitor 1 (set on secondary monitor for extended desktop).
When i boot the computer until windows log in screen both monitors are open and shows the same thing. When windows log in screen only monitor 2 is open and when i log in on windows i press the source button on monitor 1 and then windows finds monitor 1 again and plays as normal.
My system :
Gigabyte 990fxa ud5
16 gb ram
Amd RX480 from Asus
Windows 10 x64 1607 built with latest updated and latest drivers.
Sounds exactly like what is happening to me, except that the source button doesn't help. I have to reboot or unplug/plug.
I wonder if using a second DP to HDMI cable instead would work? I doubt it though, because it's the same monitor whether I plug it into my existing DP to HDMI adapter or directly into the HDMI port.
I have exactly the same problem with my brand new RX480.
Both monitors display fine the boot process and I can see the BIOS info on both monitors.
As soon as it gets to the Windows 10 login screen, the second monitor stop displaying and reports a signal loss.
I have to unplug the HDMI cable from the monitor, wait 3 seconds, and then plug the cable in. Then it works fine for the duration of my computer use.
To me this sounds like a driver issue, not hardware related.
When I removed the driver and ran with just the Windows standard driver, I did not have an issue. Granted that I couldnt continue running without the AMD drivers as the Windows drivers only mirror the screens and not extend.
This is very annoying, as it seems that AMD quality of coding the drivers is left wanting.
I've updated yesterday to 16.8.3 drivers and the problem persists.
As a side note, the Radeon control panel is absolute rubbish compared to the Nvidia software.
I have the same issue,
RX480 Saphire, running dual monitors, both on HDMI, the "login" monitor always shows no signal, on the other I get signal and the cursor moves around. If I unplug and plugin either HDMI they both come back to life and are fine until next shutdown and boot
Swapped cables, ports and monitors around, feels like drivers
Any suggestions welcome
as u saw above i had the same issue.
i updated my drivers to version 16.9.1 and for two days now every time i restart or power up my computer both of the monitors open normaly.
Try to update to 16.9.1 and lets hope your problem will be solved !
same issue with a different config, so I'm not sure whether this is the right topic for me
(from the issue side yes, from the card side no) please redirect me if not
VGA Card: desktop HD 4850 (good enough, since I gave up FPS gaming after 20 yrs or so...), two DVI monitors
driver: 8.970.100.9001, win 10 Pro 64bit, extended desktop
it worked fine for a long while, but since the latest windows automatic update I experience similar symptoms:
BIOS boot : fine
Win boot: under the spinning circle phase before the login screen the primary monitor goes to sleep, the secondary is dark, but working
if I (with no signal on the primary screen) do a "blind" login, the secondary monitor comes alive with the background, but still nothing on the primary
if I unplug the primary monitor cable and re-plug everything goes back to normal
changing ports, cables did not solve the issue
I was advised to change to driver 15.301.1901.0, but it doesn't work for me, if I install or choose that, I end up with the MS basic display driver, so I have to opt back to 8.970.100.9001
Only because there are no helpful replies, here's a workaround.
I have the same issue on a Windows 10 machine and a Radeon HD 4600 . My primary display is the DVI output, and secondary is VGA display. VGA never has a signal upon bootup.
Rather than physically unplugging the cable, I found the quickest workaround to click on the Notification button on bottom right, then Project, then "PC Screen Only", then "Extend". That seems to reset the display settings to Windows, and doesn't require physically manipulation of the cable.
I remember, years ago, coming across a command line utility that resets the display settings. I can't seem to find it now, but I did find a Microsoft utility that seems to do the same thing.
That would be a handy solution that you can script at the command line, though it'll require admin privileges.