NES cartridge battery replacement woes

[HunterZ]

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)?

[brandonk318]

This sadly reminds me of the time I had to replace a battery for my golden sun. Well, my cartridge apparently had trouble too but the battery clip broke off and I resoldered it to the board and it acts as if there is no battery. I couldn't figure out how to fix it. Might have to get the game replaced

[tsukasa]

IIRC most NES games use 8KB srams for the save ram, so replacing it shouldn't be an issue, though I doubt your save ram has been damaged unless you're really bad at soldering.

You'd probably do more damage than good in the process of trying to replace the sram.

[HunterZ]

IIRC most NES games use 8KB srams for the save ram, so replacing it shouldn't be an issue, though I doubt your save ram has been damaged unless you're really bad at soldering.

You'd probably do more damage than good in the process of trying to replace the sram.

Any idea what *could* be the problem then?

[HunterZ]

Okay so I'm a TOTAL idiot. I was trying out NES emulators on my new HTPC(*) and I noticed that Crystalis has a hard-to-find save/load menu that I had forgotten about. When testing my real cart previously, I was mistakenly trying to "save" by resting at the inn (that method seemed to actually work across resets but not power cycles, I think because the game may have been autosaving to the NES RAM or something).

At any rate, I reassembled my real Crystalis cartridge just now and tested it out and it works fine Now it's got a new battery and some new capacitors, so it should last another 20 years lol. Probably for the best since the original battery was down to under 0.3V or so anyways (~10% of full voltage).


* - anyone have recommendations for NES emus under Win7? FCEUX and Nestopia have slightly stuttery/skippy sound, and RockNES has a horrible GUI. JNES seems fairly decent, but the emulation isn't as accurate (I noticed some jittering in parts of Crystalis that isn't present in most newer NES emus or on a real NES). SNES9x and Fusion (Kega) run buttery smooth my HTPC, so the stuttering sound of NES emus is driving me nuts