Second display not working

[kilrah]

Hi there,
I have a 22" iMac (2013) for about 6 month. Since day one I had a second monitor attached (LG flatron E2241) and everything worked fine.
About a week ago the second monitor stopped working. If I tried to disconnect/reconnect the cables (displayport, adaptor, or DVI - I tried them all), the main iMac screen would blink for a sec and continue working. The main screen did nothing. All the connections are now fine, I double-checked them.
I tried safe mode, PRAM and SMC reset. The second screen just stays in standby.
Any suggestions?

Thanks

 

[Bear]

If you got the Mac 6 months ago it can't be a 2013 model. It is probably a late 2012 model.

Have you checked the settings on the LG display? I remember someone else having an issue like this and it turned out to be the display was somehow set to a different input.

 

[kilrah]

The display is on DVI power saving mode.

 

[jaxhunter]

Does the display have an input selection button? My Dell monitors have 3 options: Auto, Digital (DVI) and Analog (VGA). I usually leave it in Auto and it picks up the active signal. Occasionally my roommate switches it over to VGA for his laptop and then doesn't put it back on Auto or DVI for the Mac. When he does, my display acts the same way, though I am now used to the behavior. So first step would be to make sure the input is correct.

Second, try connecting the display to another computer somewhere and see what happens. Try to find a machine that will connect with a direct connection (a machine with a DVI port, for example) that does not require an adapter to operate. If the display works like this then try a new adapter with your iMac.

Third, try a different cable.

Fourth, borrow a display and try it with your iMac. See what happens.

This will help you to determine if the problem is the monitor, adapter, cable or computer.

 

[kilrah]

Sounds like a good solution (or at least a path to the solution). now doing it is not so easy...

Thanks

 

[kilrah]

Well, that's strange. I had a power outage and after I restarted the computer, everything is back to normal; multi-monitors works like charm.

Thanks all for the help.