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gernberg

Member

Registered: 2011-05-22

Posts: 3

"No signal" on DisplayPort after turning screen off.

I've encountered a strange error with my new monitor / graphics card.

If I leave the computer on the monitor goes idle - and wakes up when i move the mouse / touch the keyboard (as expected).

But if I turn of the monitor by pressing the power button (on the monitor) I can't wake it up again - the monitor reports "DisplayPort: No signal" and then goes idle.

I've tried:
* "hard" rebooting the screen (unplugging the power)
* Switching between different TTYs and X (I know I'm in X and the computer is responding)
* Restarting X (switching to TTY1 -> Ctrl-C and then run startx)
* Unplugging the DP-cable and plug it back in
* Plugin a DVI-cable instead of DP

Any suggestions on what to search for / what could cause this problem?
The monitor is a: ASUS PB278
My graphic card is a: XFX Radeon HD7770

MichaelTunnell

Member

Registered: 2014-07-28

Posts: 14

Website

Re: "No signal" on DisplayPort after turning screen off.

I know this is very old but in case someone else has this same issue as I did the fix was actually rather simple when you realize the problem. DisplayPort has a weird issue regardless of the monitor because some motherboards stop sending the signal when the monitor is turned off due to a "power saver" feature in the monitors.

I have an HP Monitor that had this issue and I found out that Samsung also has something similar when it comes to their monitors. I don't know about ASUS but I think it is safe to assume that it might be an issue with DisplayPort itself rather than the manufacturers.

Here are the solutions I found, this forces the monitor to use the original signal so it doesn't need to be resent to the monitor.

HP:
Monitor Menu -> Source Detection -> Low Power (Power Saver) -> change to "Always Active".

Samsung:
Monitor Menu -> Setup & Reset -> Magic Return -> off

ASUS: (not tested, just a hypothesis)
Monitor Menu -> System Settings -> ECO Mode -> turn off

Last edited by MichaelTunnell (2014-07-28 16:57:43)

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