I recently bought a PS2 Slim. It seems to work fine. I didn't realize I needed a PS1 memory card, so without much thought, I bought the cheapest one on ebay. The brand is Hyperkin (so it's not official), and it came in a sealed package.
I put it in, fired it up, and when I tried to save a Gran Turismo 2 file, I was prompted to format the card, so I did that, saved my game, and restarted the system. The save was there, so everything seemed fine.
I played about 10 hours between various games, saving and loading just fine, using 5 or so blocks (I definitely didn't fill the card). Then while playing FF7, after having saved a few times already in my session, when I tried to save again, I was prompted with "Memory card not formatted. Format now?". I wasn't really thinking, so I just said "yes". My other saves were now gone, but I was able to save the current game, and just continued playing.
I lost the progress in my other games but I hoped it was just a one-time glitch because the card was "new" or something, but I continued to use the card after this, and I was able to save and load normally for another 15 hours of play between my games.
And then it did it again. I was playing FF Tactics, I had already been playing for an hour or so, I had saved just fine a few times, and suddenly when I tried to save again, I got message saying "Game data corrupted", and then after hitting OK, I got the "Memory card not formatted. Format now?" message.
The PS2 browser now sees the card as an unformatted card.
My question is: are these normal symptoms of a bad card, or is there any reason I should think the PS2 itself is bad? I realize the common wisdom will suggest to get an official Sony card, but has anyone else tried this particular card with a PS2 slim?
I've put a couple hours into FFX with a PS2 card and it seems fine so far, so I suppose if that card gets corrupted somehow, then I will have a clear answer.
I'm going to try getting an official sony ps1 card, but is there anything else I'm not realizing about this issue? Another question here suggests only certain PS1 cards work well with the Slim