Epson LQ-510 User Manual page 42

Using Single Sheets
2. Turn on the printer. (The green POWER light should come on.)
Note: Do not insert paper in the printer before turning on the printer.
3. Move the left edge guide so that it locks in place next to the
guide mark. (You may want to change this position later,
depending on the margin settings of your application program.)
Paper Handling 2-3