Question My PC instantly crashes when i plug the second monitor in

[HardCoreSnowBall]

so, i've been trying to figure this out for WEEKS and i desperately need some ideas or help to get my setup working. as the title says, as soon as i plug the second monitor in, the screen goes black on my first monitor (and the second one doesn't turn on either) and my PC crashes and is unable to boot in any way (both screens remains without signal for as long as both monitors are plugged in AND until i restart the PC). i'm plugging both of them in via HDMI and both GPU HDMI ports work correctly and both monitors work correctly when plugged in individually.

PC details:
CPU: Ryzen 5 1600
MB: B450M Pro4
GPU: RX580 Sapphire Nitro+ Special Edition
RAM: 16GB
PSU: Gigabyte G750H 80+ gold modular (750W)
OS: Windows 10 Home 64-bit

1st monitor: Acer B246HL (1920x1080)
2nd monitor: Philips 170C (1280x1024) - an older monitor from my first PC

i have tried the same thing on a completely different configuration, where only the GPU was the same (on my old setup) and the results were the same, so i'm suspecting the problem is in the GPU. i haven't messed with the GPU BIOS at all. the drivers are all up to date and i have tried the original drivers too (from my GPU's CD). i reinstalled windows 10 several times as well and i tried different order of plugging said monitors in. i'm all out of ideas and i really need some help in resolving this.

 

[rgd1101]

make and model of the psu

 

[HardCoreSnowBall]

make and model of the psu

Gigabyte G750H 80+ modular (750W PSU)

 

[HardCoreSnowBall]

still open and unresolved :S

 

[Mtop]

Are you running the 1280 x 1024 monitor at 1920 x 1080?
or are you running them both at 1280 x 1024?
Toss the old 1280 monitor and plug in another 1080P monitor

 

[HardCoreSnowBall]

Are you running the 1280 x 1024 monitor at 1920 x 1080?
or are you running them both at 1280 x 1024?
Toss the old 1280 monitor and plug in another 1080P monitor

i have tried several other monitors over these couple of days. tried plugging in a 1080p one, 720p one, with a TV, even tried changing all the resolutions - the result is the same, the main display flickers for a second and a sound of new plugged in device is heard and immediately after that, the main screen goes black and the computer crashes.

 

[saratran]

I'm having the same issue as yours too. Just bought a 2nd hand Nitro RX 580 SE and couldn't get dual monitors to work. Mine doesn't black screen crash instantly but 2-3 minutes after (even when idling). Ran some stress tests with single monitor mode - all fine. I've tried 3 different GPU drivers, all results in crashes. Tried a clean install of Windows, doesn't work either.

My PC specs:
CPU: Ryzen 5 1600
MB: Asrock B350M Pro4
GPU: RX580 Sapphire Nitro+ Special Edition
RAM: 8GB
PSU: MWE Bronze 550W

EDIT: It was the HDMI splitter that causes the crashes! As soon as I connect one of my monitors directly to the GPU or connects the HDMI splitter to a 5v power source, the crashes stop. Why in the world that an HDMI splitter can crash my whole system is just mind boggling?!