Visit archive.org and use the "Wayback Machine" to look at old manufacturer URLs from 2012–2017. Often, the PDF was publicly accessible back then but has since been removed from the live web.
The manual begins with a diagram of the device. The Ice 680 R typically features an LCD screen, a numerical keypad, and function keys (F1, F2, etc.). supertester ice 680 r manual pdf
Email the current brand owner (e.g., Testo North America). Provide the model number and serial number of your unit. Ask politely: "Could you provide a PDF copy of the original user manual for the SuperTester ICE 680 R?" Support teams maintain internal archives. Visit archive