gps-icesailing

My old GT 31 will not recognise the sd card, I have tried a couple and they work on my other GT 31. Have installed navilink 2 but cant get the GT 31 to open, can someone tell me what I am doing wrong - thanks

Try to put some painters tape on the top of the card.
After all those years the tollerance can be off a bit.

SEVERNE