Ground Loop ( Lenovo T430 + 23 inch Lenovo Screen connected via VGA )
In the roll out phase of swapping users from desktops to laptops + one external screen as per the title, I think I haven narrowed the issue down to a ground loop ( however cutting or disconnecting the earth wire from one of the mains plugs for either the monitor or laptop is not going to happen due to obvious health and safety reasons.
Linky here - External monitor flicker, laptop ground loop problem solved | Countdown to critical mass mrgnome.wordpress.com
Found this as well : http://voices.yahoo.com/rid-yourself...92.html?cat=15
Although purchasing at least a few hundred universal ac adaptors is going to be out of the question and as above getting an adaptor or removing the earth / ground wire is not an option either.
Basically it is causing issues on the external monitor when you have the laptop plugged in via mains ( using the original official laptop mains power supply / charger )
The only other suggestion I have seen and reading on forums has not helped is to use or try a thicker shielded vga cable ( the 23" monitors we are using also have HDMI and mini display port or display port connectors as well as vga )
I think we are ordering in a few cables to try the display port to hdmi and see if that helps with the ground loop issue which is causing the shimmering / refresh rate issue
Just wanted to know if there was anything I could get or do to sort out the ground loop issue ( I think there was a post on edugeek a year or two ago ref ground loop but effecting audio not video , where as for us it is effecting the video output on the external monitor )
Any idea on what was used to get rid of the ground loop issue for the audio ? Just wondering if a similar device could help us out ref the external display whilst said laptop is connected via mains.
@Arthur, @Millgate or anyone else ?
Monitor Model : lt2223pwc - user guide --> http://download.lenovo.com/ibmdl/pub...223p_ug_en.pdf
Laptop Model Number : 2349KQ1