So suddenly neither of my two beloved PCM-10s will recognize new or used 16 or 32 gb San Disk Micro SD cards, even though one of them has been happily using such a 32 gb card for years. I bought new cards of this ilk (both 16 and 32 gb), only to find that neither PCM-10 will recognize these cards, let alone let me format the cards in them. The only card that I have that either of my PCM-10s will recognize is a San Disk "M2" 16 gb card that the other PCM-10 has been using for years. I popped this M2 card out of the one and put in the other, where it was recognized immediately.
Trouble is, I cannot find another "m2" card for sale on line, except for a high price and less capacity (e.g. , $30 for a 4 gb card). Any thoughts or suggestions?