My c902 has suddenly stopped recognising the m2 card

This may have something to do with how the m2 card is formated. PC systems such as FAT32 and NTFS do not work with cameras or telephones as the data cards in these devices are formatted to FAT16 or lower. In order to read the card when you placed it in your PC FAT32 would have been used.

If you are prepared to loose the data on the card I suggest you use a PC to re-format it to FAT16, your phone should then recognise it again!

I have c902 use mamery card m2 1GB many time no file