So I pulled Crystalis off the shelf a week or two ago and played it for a couple hours, then saved my game and turned off the NES. When I came back the next day, booted up the game and hit Continue, I found that my save data had been lost I did some testing and found that the game retains the save data if I just reset the console, but if I power off it gets lost (even if I'm diligent and hold down the reset button while powering off).
Earlier this week I got a fresh CR2032 battery (the kind in the cart), and the other day I finally got around to replacing the dead one (0.3V remaining of 3.2v or whatever it is that a fully charged CR2032 starts at). Unfortunately, the game still wouldn't keep my save data!
I tested and made sure that the battery was supplying power to the contacts on the board (since I had cut off the old battery and soldered on some wires to a battery holder salvaged from an old PC motherboard) and it was. I changed out the 2 non-ceramic capacitors nearby in case they had dried up (they didn't look bad but you never know). No luck. I even tried reversing the polarity on the battery just in case I had screwed that up, but that didn't make any difference either.
Any idea what's wrong? I don't see any signs of damage on the board, and it did work a couple years ago when I last played it. The only thing I can think of at this point is maybe the SRAM chip was damaged by heat when I was trying to remove the solder around the battery clips; is this likely? If so, would it be a good and/or workable idea to try to replace the SRAM chip with one from, say, Dragon Warrior (I have 3-4 copies of that, so parting one out is an option)?
Earlier this week I got a fresh CR2032 battery (the kind in the cart), and the other day I finally got around to replacing the dead one (0.3V remaining of 3.2v or whatever it is that a fully charged CR2032 starts at). Unfortunately, the game still wouldn't keep my save data!
I tested and made sure that the battery was supplying power to the contacts on the board (since I had cut off the old battery and soldered on some wires to a battery holder salvaged from an old PC motherboard) and it was. I changed out the 2 non-ceramic capacitors nearby in case they had dried up (they didn't look bad but you never know). No luck. I even tried reversing the polarity on the battery just in case I had screwed that up, but that didn't make any difference either.
Any idea what's wrong? I don't see any signs of damage on the board, and it did work a couple years ago when I last played it. The only thing I can think of at this point is maybe the SRAM chip was damaged by heat when I was trying to remove the solder around the battery clips; is this likely? If so, would it be a good and/or workable idea to try to replace the SRAM chip with one from, say, Dragon Warrior (I have 3-4 copies of that, so parting one out is an option)?