Question I can't get all three monitors to work at the same time ?

[mnm313]

Hello friends,

I recently bought my 3rd monitor. But I couldn't manage to get all three of them to work at the same time. 2 monitors work but I have to disable the other one to activate the 3rd one. I can get images from all monitors but more than 2 are not active at the same time.

- I use AMD HD 6850 as a graphics card.
- My 2 monitors only have VGA inputs.
- My 1 monitor has VGA + DVI-D inputs.

I am trying to transfer from the graphics card as follows;
- Passive converter from DVI to VGA.
- Active converter from HDMI to VGA.
- Active converter from Display Port to VGA. (I am not sure if it is active but I will leave the sample image below)

I have been researching for days but I could not reach a conclusion. I am only considering the possibility that the DP to VGA adapter is not active. Thank you in advance for your help.

1st adapter: https://ibb.co/P6qYdSf
2nd adapter: https://ibb.co/TPQ1CzT
3rd adapter: https://ibb.co/SRc9P4s

 

[Glenwing]

This is expected since Radeon HD 6850 has the restriction as described here:

https://linustechtips.com/topic/729...v2/?section=active_adapters_for_multi_display

Except that the DisplayPort to VGA adapter should work since all DisplayPort to VGA adapters are active. Perhpaps internally it is designed as a DP to DVI passive adapter followed by a DVI to VGA active converter...

 

[mnm313]

This is expected since Radeon HD 6850 has the restriction as described here:

https://linustechtips.com/topic/729...v2/?section=active_adapters_for_multi_display

Except that the DisplayPort to VGA adapter should work since all DisplayPort to VGA adapters are active. Perhpaps internally it is designed as a DP to DVI passive adapter followed by a DVI to VGA active converter...

very solid guide, thanks for sharing.

If I understood it correctly, there should be no problems with my setup. As it says, I am using a display port > active vga converter for the 3rd monitor. In this case, all 3 monitors need to be able to display at the same time.

The only thing I can think of is changing the dp > vga adapter. I have the same suspicion as you said. Already have one of the same from a different brand, I will try that tomorrow.

At worst, I think I will buy an nvidia card with a display port output at the same levels with 6800 to get this working.

 

[mnm313]

Problem solved. I'm writing this in case someone else needs it.

As @Glenwing said, the display port > vga converter I had wasn't active even though it was supposed to be. It probably had a different routing/conversion in its internal hardware or at worst it was crap at all.

If anyone has the same problem as me and can't figure out what the problem is because of the phrase "all display port > vga converters are active" on the internet, I recommend trying a different brand's converter because that's how I solved the problem. I bought a more reliable brand's converter and I'm currently writing this article using my 3rd monitor.