RipRap2020
New member
I recently purchased a CMAP 4D chart card for my GP 1870f. However, the unit does not appear to recognize that the card is in the slot. Am I missing an installation step? Also, many of the choices on the Chart Display menus (such as the "chart lock on/off") are grayed out and can not be accessed. is this a setting issue on the 1870 or is there a malfunction?