[SOLVED] ¿Why do I get video signal only if I have a VGA to HDMI adapter connected?

Jul 28, 2022
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0
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Hi guys, so I've been searching all over the internet for solution to my current problem but I haven't had luck, about a week searching and couldn't manage to fix this.

This is my build:
MOBO: Asus Prime A320M-K
CPU: Ryzen 5 2600X
GPU: Radeon RX590 Sapphire Nitro+
PSU: Corsair Cx550 550w

So I used to have two monitors hooked up to my GPU with a VGA to HDMI adapter and it worked fine with two 19" monitors and last week I bought two new Asus VG248QG monitors and hooked them up to my GPU with display ports that came with the monitors and now I cant get any signal to my monitors, I tried changing to HDMI cables and it didn't work either but when I connect my adapter all the monitors work for some strange reason even if the adapter isnt connected to a monitor. I think the problem is directly in my MOBO because I cant get any video signal in bios when I disconnect my adapter, also when I'm in BIOS or Windows if I disconnect the adapter all monitors que disconnected.


Here are some things I tried already:
Tried enabling CMS on bios
Reseated RAM, GPU and resetted bios by removing CMOS battery for a few minutes
Reinstalled GPU drivers
Updated BIOS
 
Solution
Okie, use the adapter to get the vga and get into bios. I believe it's under the main settings, but there's an option for pcie detection. If it's at default it'll say Auto. Change that to Gen3. Save, exit. Hopefully that'll work.
Hey Karadjgne sorry for my late reply and thank you for your help although I didn't find any options in the BIOS Menu regarding the PCIE Detection but what i did find was an option called "Resize BAR Support for harnessing full GPU Memory" and it fixed my problem but it was strange because I needed to disable right after enabling because it disabled CSM and I need it enabled because my Windows is installed in an MBR system so I needed the legacy support and it was still fixed by disabling Resize BAR...

Ralston18

Titan
Moderator
This GPU?

https://www.sapphiretech.com/en/consumer/nitro-rx-590-8g-g5-oc_c

Are you using 2 monitors or 4 monitors? I believe 4 - no harm in asking to verify.

How old is that Cosair Cx550w PSU? History of heavy use for gaming, video editing, or even bit-mining?

Regarding:

"but when I connect my adapter all the monitors work for some strange reason even if the adapter isnt connected to a monitor"

Not sure about what you are explaining. Can you add more explanation or a diagram perhaps?

Specifically how are all the monitors connected?

E.g.:

GPU ---> VGA cable --- HDMI adapter ----[HDMI port] Original 19" monitor x 2

And also GPU [DP port] ----- DP cable -----> [DP Port] New Asus VG248QG monitor x 2

Edit and correct as necessary.
 
Jul 28, 2022
4
0
20
This GPU?

https://www.sapphiretech.com/en/consumer/nitro-rx-590-8g-g5-oc_c

Are you using 2 monitors or 4 monitors? I believe 4 - no harm in asking to verify.

How old is that Cosair Cx550w PSU? History of heavy use for gaming, video editing, or even bit-mining?

Regarding:

"but when I connect my adapter all the monitors work for some strange reason even if the adapter isnt connected to a monitor"

Not sure about what you are explaining. Can you add more explanation or a diagram perhaps?

Specifically how are all the monitors connected?

E.g.:

GPU ---> VGA cable --- HDMI adapter ----[HDMI port] Original 19" monitor x 2

And also GPU [DP port] ----- DP cable -----> [DP Port] New Asus VG248QG monitor x 2

Edit and correct as necessary.

Thanks for your time and sorry for my bad explanation.

What I'm trying to say is that I used to have two 19" Monitors both connected to my PC via VGA to HDMI Adapters and everything worked fine, then I decided to replace these old monitors with two new ASUS VG248QG Monitors connecting them to my PC via Display Port, this is where I have a no video signal problem but If I connect my VGA to HDMI adapter on an available HDMI output in my GPU both Asus Monitors start working. Here is a small diagram to help with my explanation.

Basically I'm only using two monitors, the adapter seems to make both monitors work. Already tried connecting my new monitors with HDMI and same problem persists.
TVj663.png

zIXBuc.png


Also my PSU is about 3 years old and the exact GPU is this one: https://www.sapphiretech.com/en/consumer/nitro-rx-590-8g-g5-se_c
I haven't done much heavy use with the GPU I mostly do home office maybe 1 or 2 hours of game every 2 days or so, no crypto mining and no video editing.
 

Karadjgne

Titan
Ambassador
Pull the gpu out and stick it in the second slot. Then boot up and you should get a signal. Go all the way into windows before shutting down. Most bios have this really bad habit of default/auto only searching for Gen4 gpus, for some odd reason it won't auto sense a Gen3 card. Using the second slot bypasses cpu pcie lanes because the second slot is chipset bound for pcie. This'll setup bios correctly for the gpu.

After that you should be able to shutdown and swap the card back.
 
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Jul 28, 2022
4
0
20
Pull the gpu out and stick it in the second slot. Then boot up and you should get a signal. Go all the way into windows before shutting down. Most bios have this really bad habit of default/auto only searching for Gen4 gpus, for some odd reason it won't auto sense a Gen3 card. Using the second slot bypasses cpu pcie lanes because the second slot is chipset bound for pcie. This'll setup bios correctly for the gpu.

After that you should be able to shutdown and swap the card back.
Hi thanks for the reply, sadly I think I can't do that because my MOBO is an Asus Prime a320m-k and it only has 1 slot for the GPU
 
Jul 28, 2022
4
0
20
Okie, use the adapter to get the vga and get into bios. I believe it's under the main settings, but there's an option for pcie detection. If it's at default it'll say Auto. Change that to Gen3. Save, exit. Hopefully that'll work.
Hey Karadjgne sorry for my late reply and thank you for your help although I didn't find any options in the BIOS Menu regarding the PCIE Detection but what i did find was an option called "Resize BAR Support for harnessing full GPU Memory" and it fixed my problem but it was strange because I needed to disable right after enabling because it disabled CSM and I need it enabled because my Windows is installed in an MBR system so I needed the legacy support and it was still fixed by disabling Resize BAR afterwards, it seems like the Resize BAR would reset my GPU detection somehow in my motherboard.

I really don't know the magic behind this, I'm just glad it worked so if anyone has a similar problem this should fix it.

Thank you all for your help
 
Solution