Here is a 136 KB PDF datasheet for the PC1601ARS-ESO-A display module, a part number that follows the Powertip pattern for 16-character, single-line character LCDs. The A revision letter and ESO option code identify this specific variant, so they should match the label on the module being serviced. Documents of this kind normally give the outline drawing, connector pinout, electrical characteristics and controller timing, which help when checking supply voltages, contrast adjustment and backlight connections during repair or replacement.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @acodis_lcd_datasheets_EDID. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.