HP LP2475W displayport bug?

[Mark R]

Since getting a second monitor, I've moved my old HP LP2475W onto a displayport connection (to simplify wiring - both monitors can connect via DP).

However, I've noticed something strange, every time the HP turns on from sleep mode (or manually) catalyst control center puts up a warning about "Displayport link failure" and switches the HP to 800x600. This happens from sleep, or if the monitor is powered off on the front panel.

It's not the cable or the graphics card port, as these have been swapped multiple times, and the monitors have been swapped with known working monitors - the problem is confined to the LP2475W.

I've noticed that the problem is worst if I set the HP to displayport only mode, as it will either not get a signal at all, or switch to 800x600.

If I switch it to "input scan" mode, then things are better - the monitor will wake up, but get no signal. Catalyst control center will pop-up the error message, the monitor will then cycle all the ports, before coming back to the DP and will sync up with a good signal.

I'm guessing that there is some sleep-mode firmware bug in the monitor which causes it to drop displayport connections when waking. Just wondered if anyone had come across something similar.

 

[taq8ojh]

Weird. I have that monitor as well and never had such problem (it's not bug-free though, sometimes it wouldn't display anything no matter what I do if I plug it into different card or something).

 

[nightspydk]

Have you considered an ati bug?

Just saying.

http://www.google.dk/#hl=en&sclient...96,d.Yms&fp=208ed2f49b534839&biw=1920&bih=909

Could be hardware I suppose but I dunno.

 

[Mark R]

Have you considered an ati bug?

Just saying.

Heh. The first link on that search page is a monitor firmware bug! In this case a dell monitor, where the dell rep on the tech support forum admits that it's a known issue with certain revisions of that model.

I've actually looked a bit further, and there's a long thread on the linux kernel mailing list where the driver developers were looking into displayport issues with the same monitor and deciding it's related to the monitor not sending the correct wake-up signals to the graphics card over a displayport conection.

 

[aceO07]

(Bumping old thread.)

Mark R - Did you ever figure this out and get it resolved? I probably have had the same issue for the past 2 years when I got my new laptop w/ displayport. I always thought it was a driver or laptop issue. It was extra annoying since I had the monitor setup as secondary and it would shift all the windows back to my primary monitor a few times a day.

I installed Windows 10 and it was still happening, so it's less likely a driver issue. My next step is to use displayport to hdmi converter and see if it still happens.