IMPORTANT: Any time you install or remove components, disconnect power to the unit before you begin. "Hot Plugging" components in this manner can cause even further damage to one or more cabinet components.
To power down a PAR+ or MSC+ cabinet, flip the master switch located in between the OSMs to the off position.
To power down a PAR+ ES cabinet, flip the master switch located in next to the transformer to the off position.
If you are experiencing this issue, check the lights on the power supply module: