Navthai : ชุมชนผู้ใช้งาน GPS อันดับหนึ่งของไทย

I have a chinese gps system the problem with it for some reason it can not see a sd card anymore it just happened on day it was fine next it done this. I have tried many different cards and they are all the same they also can be read ok in my PC. My gps system is running wince5 if that helps everything else works ok can get into wince ok but it just will not see the sd card anyone got any ideas