Monitor "Input not supported" Asus RoG Strix B450-I w/ Ryzen 5 2400G w/ Acer 27" 1080p monitor

[Dysnomia]

Just put together a Mini-ITX build (full parts list below), and I'm not getting a signal on my monitor. I've tried different HDMI cables, turning-on the system first, turning-on the monitor first, forcing the monitor input to HDMI instead of auto input. There is only one HDMI port on the motherboard, and there's no PCI-e GPU installed, so I know I don't have the HDMI cable plugged-in to the wrong connector. The monitor works fine with several other machines. The fans in the machine are spinning up, and I'm seeing LAN activity LEDs, the motherboard's RGB lighting is cycling, and the case LED is on.

I've seen some forum posts that suggest changing the PCI-e GPU vs. IGPU BIOS setting, but I can't change BIOS settings with no video on my monitor! I'm waiting for a PCI-e riser cable to temporarily connect an old HD6450, but it won't be here until Monday.

Any other ideas? I'm about ready to start RMAing this stuff. This is about my 15th build, so I'm not used to running into problems I can't solve.

System:
CPU: AMD Ryzen 5 2400G
Cooler: Stock Wraith
Mobo: Asus RoG Strix B450-I
RAM: 2x 8GB Crucial Ballistix Sport LT DDR4-2666
GPU: Integrated Vega 11, NO PCI-e BOARD INSTALLED
SSD: Samsung 970 Evo M.2
HDD: Hitachi 1GB SATA 2.5"
PSU: SeaSonic Focus SFX 450W
Fan: Noctua 120mm

Monitor: Acer S271HL 27" 1920x1080

[r.linder]

Try a different HDMI cable, the one you're using might be broken/faulty.

[Dysnomia]

I've tried two HDMI cables so far. I'll look for another one, but both the ones I've tried were working with other devices.

[Jabberwalkie Doodlebug]

Try connecting to your television. If your Television has a HDMI available, Use that. Better HDMI than regular old PC Connections on televisions where you also have to run a separate sound cable. Switch your television settings to that HDMI that is available. That is what I use, I have a 4K Television I use. I have not used a monitor in years.

[_I_]

sounds like you told windows that the display supports a res that it does not

plug in another display, use winkey+p to enable both as span
lower the res to something it supports

[emoticorpse]

Clear cmos, update bios?.

[Dysnomia]

引用自 _I_：

sounds like you told windows that the display supports a res that it does not

plug in another display, use winkey+p to enable both as span
lower the res to something it supports

Windows isn't installed yet. It isn't even displaying the BIOS/UEFI screen.

[Dysnomia]

引用自 emoticorpse：

Clear cmos, update bios?.

I think there's a jumper to clear the CMOS, and I'll try that next, but I don't know how I'm going to update the BIOS without being able to see the BIOS screen. This board isn't supposed to need a BIOS update to work with this processor.

[Dysnomia]

引用自 Jabberwalkie Doodlebug：

Try connecting to your television. If your Television has a HDMI available, Use that. Better HDMI than regular old PC Connections on televisions where you also have to run a separate sound cable. Switch your television settings to that HDMI that is available. That is what I use, I have a 4K Television I use. I have not used a monitor in years.

I'll try that.

[Dysnomia]

Bought a new HDMI cable, bringing the total number of HDMI cables I've tried to 3, but that didn't help.

[Dysnomia]

Well, I'll be a monkey's bare-a$$ed uncle! Got an HDMI to DVI-D cable and hooked it to one of my old NEC Multisync 5:4, 1280x1024 native panels from about 12 years ago, and the ASUS splash screen came right up. Weird that a 2 year old HD panel won't work, but a monitor that's a decade older will!

[Witski]

mhh if you have a r1 series acer 27 " look if the monitor menu have auto detect on cables, on that you can choose hdm vga and dvi displays, i had mine on vga and auto detect off, i switch to hdmi and worked, i don't understanf if you manage to make it work, anyway you could try this if you haven't yet.
I buy mine acer r1 r271bbmix Friday and is a great jump in quality and biggerness from my old benq 21" from 10 year ago

[Dysnomia]

Tried both auto input and setting it to HDMI, and there are no other cables connected. The monitor displays a different error when there's nothing connected to the active input.

[Witski]

mh try the dvi adaptor on it, if doesn't work,
1 Is the resolution, and you need to reflush the bios (is what the tecnician did to me when i take the pc to repair to a similar problem)
2 the monitor is defective.
i exclude the 1 because you managed to open it in an older monitor.. im out of option to think about, if i see something on internet i will tell you

[Walach]

This is probably not the same issue but I had a problem with HDMI that was caused by to long cables. I learnt that it's not that you get a worse image or framerate with HDMI but that you get NO image with to long HDMI cables.

Just something I wanted to add, I think it was something like 4-6 meters before HDMI didn't show a picture at all. But again, I know little about this stuff and it's probably not the cause of your problem but I wanted to give my 'poor' advice/idea on it! :D

[Andrius227]

引用自 Walach：

This is probably not the same issue but I had a problem with HDMI that was caused by to long cables. I learnt that it's not that you get a worse image or framerate with HDMI but that you get NO image with to long HDMI cables.

Just something I wanted to add, I think it was something like 4-6 meters before HDMI didn't show a picture at all. But again, I know little about this stuff and it's probably not the cause of your problem but I wanted to give my 'poor' advice/idea on it! :D

That depends on the cables. I actually have a 10.6m long hdmi cable that i use for my ps4. Although that particular cable only works one way, it has a dedicated input and output.