I just got this monitor used and everything appeared to be working fine. When I got it home it started switching several times between analog and digital then it goes to the "check signal cable" box. The menu will not pop up. I got it to the first time but it wouldn't do it again. I have two of these. Identical monitors. The other works fine. I'm using the DVI and switching it to VGA is not an option. MY video only supports HDMI,DVI, and display port. If it's a busted soldering weld on the connector is it something that can be repaired? Any suggestions are much appreciated.