New battery, but then save corrupt error when testing

[codezer0]

Here's the skinny.

Pokemon crystal version cart. Its original battery is long dead. Friend tried to separate original battery and reuse its tabs with a CR2025 rechargeable battery. In their attempt, it simply would wipe the save when trying it again after unplugging the cart or even simply turning it off and back on.

I gave it a try myself with my own soldering tools, as well as scrubbing away the excess solder with some desoldering braid and a fresh application on the battery at both sides, and the parts where the tabs contact the PCB.

Currently, the game will save and if I soft-reset, it will come up and restore fine. However, if I unplug, remove the cart, reinsert and power on, it does show the correct time, implying the battery is correctly keeping the RTC going. But trying to load the save gives a "save file is corrupt!" error. What are my options for this? Preferably, nothing I need to buy additional stuff for.

 

[codezer0]

An update on my end.

Found an indie game shop that was selling pre-tabbed, new batteries for these cartridges for cheap enough to pick one up.

Managed to do the cleanest soldering job in history to clean up the old battery's mess and solder this one on.

But as soon as I turn off the game, and turn it back on, the save is gone again.

What the hell? Can someone please help?

 

[koffieleut]

Did you dubbelcheck the polarity of the battery?
And you can also try to full reset the game, I thinkit was on the title screen where youmust push up, select and B. Then it asks you if you really want to destroy your savefile. Push yes, maybe it helps.
Did my own cartridges without any hassle and even managed to held on to my save from gold while using a gbasp.
Good luck.

 

[codezer0]

Well, desoldering the battery completely wipes the save anyway.

But anyway, Just had to stop and take a break, and watch some how-to videos on replacing the battery before trying again. And thankfully, some fresh tinning of the pads on the PCB allowed me to realize that one of the terminals had separated. Fixing that, and the game worked properly again, with the new battery.