Please enter your system specs so we know what we are talking about. You do this via the User CP > Edit Options page.
Did you remove the two new sticks to see if the problem went away?
You might also swap monitors (after making sure all video and power cables, inside and out, are still securely connected) with another computer. If the problem follows your monitor to the 2nd computer, you know the problem is in your monitor and not the computer. If the 2nd monitor does the same thing on your computer, then you know the problem is in your computer.
While adding two more sticks of RAM typically does not require a bigger PSU, if your old PSU was already stretched thin, the additional demand could put it over the top, especially if getting old too (as PSUs get weaker over time).
Adding more hardware can also place increased demands on case and PSU cooling. So make sure everything is free of heat-trapping dust, and that all fans are spinning properly.
Did you remove the two new sticks to see if the problem went away?
You might also swap monitors (after making sure all video and power cables, inside and out, are still securely connected) with another computer. If the problem follows your monitor to the 2nd computer, you know the problem is in your monitor and not the computer. If the 2nd monitor does the same thing on your computer, then you know the problem is in your computer.
While adding two more sticks of RAM typically does not require a bigger PSU, if your old PSU was already stretched thin, the additional demand could put it over the top, especially if getting old too (as PSUs get weaker over time).
Adding more hardware can also place increased demands on case and PSU cooling. So make sure everything is free of heat-trapping dust, and that all fans are spinning properly.