Check the back of the case for small holes and icons or letters above them. On most, not all, monitors that is where you can make some adjustments with some TV-Plastic Tools. You can get those fro Radio Shack (their online store is still open) for about $5, no more then $10.
On some Apple Monitors, there is a plastic door on the back like the old 512K/Plus Battery door. Open that door and there will be adjustment holes you can tinker with - again with plastic tools.
You do not want to use metal screwdrivers as 1) You can get a shock from it. And 2) you can break the tiny pot in the hole. The plastic tool would start to bend when you reach the end of travel of the pot while a metal screw driver will break the pot.
On some Apple Monitors, there is a plastic door on the back like the old 512K/Plus Battery door. Open that door and there will be adjustment holes you can tinker with - again with plastic tools.
You do not want to use metal screwdrivers as 1) You can get a shock from it. And 2) you can break the tiny pot in the hole. The plastic tool would start to bend when you reach the end of travel of the pot while a metal screw driver will break the pot.