"My screen appears blank, but my online button is flashing, so I know my time clock is getting power."
You must adjust the contrast.
If you open up the white face, there will be a screw on the back of the time clock labeled contrast.
When adjusting the contrast, it is very important to be gentle with the screw. Some people prefer to use a small, micro-sized flat head or Philips screw driver, but the contrast screw can often be adjusted using the tip of your finger.
The adjusting screw is highly sensitive, so make sure to turn it as slowly as possible while facing the screen to monitor the output.
If you find that you have turned the screen from blank to a completely black screen, continue turning in the same direction. Very often, the screen's display will appear after the black screen. This most often occurs if you are turning the screw clockwise.