Key combinations listed below  work as described on Andrew's GM100. They may or may not work similarly on other LEI receivers. Consider yourself warned, the risk is yours...

Time used

Press: MENU, select  SYSTEM SETUP, select SYSTEM INFO, press DOWN 5 times “Time Used” screen should appear.

Status

From “STATUS” screen go “DOWN” 5 times.

GPS SETUP

From “STATUS” screen go “UP” 5 times.

GPS RESET

WARNING !   This operation may remove all stored information (Waypoints, Events, Plots) from the GPS so do not do it unless you have to.

Press the MENU key and POWER key together. Right away after the GPS powers up press the MENU and POWER keys together again.

DIAGNOSTICS

WARNING !   Do not select FINAL SETUP. It removes all stored information, but it also may affect some factory set parameters. Just entering the DIAGNOSTICS resets Com Port settings and possibly a number of other options to factory defaults.

Hold down the UP and DOWN arrow keys and press the POWER key, continue to hold down the arrows for a short while after. The self test screen indicates (hardware?) version. Mine is 1.83