External monitor flicker, laptop ground loop problem solved
Are you having problems with a flickering external monitor on your laptop?
Does the flicker go away if you remove the laptop charger?
If you answered yes to the above questions, you probably have a ground loop. Slimplified this is because the monitor is grounded (using a 3 prong coord) and the laptop is not grounded.
What you need to do is disable the ground for the monitor. If you are using a european 240V connector just put some scotch tape over the sides of the connector, that is the ground. Check that the tape does not break when the connector is inserted. You might have to put several layers of tape on the connector.
If you have other connector types you can take a spare power cable and remove the ground prong for the monitor, or you could just use an adapter that only has 2 prongs but accepts three, like this one:
After this the flickering should go away.
BEWARE your monitor is now ungrounded, so don’t use it in the bath-tub.
Good luck!
