Epson 1500 - Manual (Page 145)

Reinstalling the controller board
1. Fit the right edge of the controller board into the right
groove inside the slot of the printer. Then gently slide the
board to fit its left edge into the left groove.
2. Slide the controller board into the printer. Press firmly on
both sides of the bracket to lock the board into place. If the
controller board does not fit smoothly into the printer, do
not force it. Remove it and make sure the edges fit properly
into the grooves inside the slot.
Options 5-31