DisplayPort to HDMI not working for ED272

I have a PC using a Radeon RX570 video card...the card has 1 HDMI and 3 DisplayPort connectors. I recently bought an Acer ED272 monitor to go next to my Samsung C24F390 monitor for this computer. Given both monitors have HDMI and no DP connections I bought a simple DP male to HDMI female adaptor.

Image: https://us.v-cdn.net/6029997/uploads/editor/7g/ybhdl5pwsu5p.jpg

I plugged the Samsung into the DP adaptor using HDMI and the Acer directly into the video card's HDMI port and everything works fine, both screens run at 1920x1080 as expected. I use the larger Acer as my main monitor and the Samsung as a secondary sitting to the Acer's left. For some reason in Win10's display properties the Acer shows as monitor 2 and the Samsung as 1. No big deal at all, i just use the display settings to make monitor 2 (the Acer) my main display.

The other day though I moved my PC setup around which involved disconnecting both monitors. When I plugged them back in I switched the HDMI cables without realising...and strangely the 27" Acer went to 640x480 resolution, with the Samsung staying at 1920x1080. I couldn't change the Acer's resolution in display properties. I rebooted the PC, powered off/on the monitors, tried various things. But then when I switched the HDMI cables back so that the Samsung's HDMI goes into the DP adapter, it went back to normal. So now I'm curious to know why the Acer can't use the DP to HDMI adapter but the Samsung can?

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juzdu

Just to add to this, I tried turning everything off and plugging only the Acer ED272 into the video card via the DP to HDMI adapter. Once I powered everything on the monitor just said "No connection", and I couldn't even bring up the monitor's OSD menu. So i switched the HDMI cable out of the ED272 into the Samsung and it came up fine. So there's something the Acer just doesn't like about this DP adapter I guess?

Cosmatic0reo

Yes, I have the same problem as you and I have no idea how to fix it, I bought that same product and an AMD Radeon video card. my computer also has 1 HDMI port and 3 DisplayPorts. However, I'm stuck because... both my monitors are Acer. So what should I do?

juzdu

Nobody ever answered my question so I'm not sure you'll get a response. I ended up giving my Samsung monitor to one of my kids and buying a 27" AOC to go alongside the Acer. The Acer runs off my video card's HDMI output and the AOC has a DP input so I go DP to DP for it, don't need the adaptor any more.

There's a whole lot of info here that it might be explained in, but basically it says going from a DP output on a PC to a HDMI input on a monitor should be well supported.
https://www.barco.com/en/news/displayport-to-hdmi-conversion-should-i-use-an-active-or-passive-adapter

billsey

Often the key is the adapter you purchase. As you can see in your image the adapter is DP to HDMI and very much not HDMI to DP. IIRC one way is quite a bit more expensive than the other, so people tend to get the cheaper one but need it backwards from what they get.

juzdu

billsey said:

Often the key is the adapter you purchase. As you can see in your image the adapter is DP to HDMI and very much not HDMI to DP. IIRC one way is quite a bit more expensive than the other, so people tend to get the cheaper one but need it backwards from what they get.

I don't understand how that was my problem though. The pic clearly says "The DP must be the source", which it is in my case. And it worked for my Samsung monitor but not my Acer. So I plugged this adapter into the PC's display port, connected a HDMI male to male cable to it and plugged it into the HDMI port on the Samsung, works fine. Move the HDMI cable into the Acer, doesn't work. So the adaptor is definitely 'converting' DP output to HDMI input for Samsung, why not Acer?

billsey

I was responding to our camper, not to you. You have the correct adapter based on the image you posted. I assume you have tested the Acer monitor on the HDMI port as well, without an adapter?