When the unit is turned off, keep the POWER and ENTER/MARK keys pressed until a test page is displayed:
| Real screen size: 81 mm × 54 mm (33⁄16 in × 21⁄8 in) |
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| All keys, except the PAGE, UP and DOWN keys, have been pressed at least once and they passed (coloured green). Other tests were passed too. The backlight level may be increased by the UP key and decreased by the DOWN key. Pressing the PAGE key more than once will display more test pages (for testing colours, grey scale, geometry etc.). |
Garmin 276C key functions. Functions in parentheses are not marked on the keys. | ||
When the unit is turned off, keep the POWER and QUIT keys pressed until this question is displayed:
Warning! Answering Yes to the question will erase all user supplied data (such as tracklogs, waypoints and routes) and preferences (such as setups), and the whole unit will be set back to factory defaults.
(It has been reported that this one works for GPSmap 376C, any other?)
When the unit is turned off, keep the POWER and OUT, QUIT, NAV/MOB keys pressed for 10 – 12 seconds.
Warning! This will clear all data including the almanac data and temperature compensation curves for the crystal oscillator! Eventually the compensation curves will be reconstructed, but it takes time; see http://gpsinformation.net/main/diagnost.txt.
If the unit "crashes" (as Windows may do) when flashing firmware or it does not power-on, try re-flashing the firmware:
When the unit is turned off, keep the POWER and PAGE, ENTER, DOWN keys pressed to turn on the unit. Also keep the last three keys pressed when re-flashing the firmware with a good copy.