Also does all menu options end up the same way? if it's damage for good it does not matter, they can be formatted somewhere in the menu but it can't fix what's beyond fixable.
The memory bank is built into the Duo line, IFU, TenNoKoe2, TGCD Dockstation but they all rely on battery backup. There is that weird bank to that's only supported by some JRPG and is big as hell and connects to the controller port...
But it's only the TenNoKoe(1) Hucard that holds the memory without battery backup, which mean it can be stored nearly forever... well unless it electrically breaks like this one..
With modern technology like the Turbo EverDrive it can also be stored forever and shared and stored on other mediums but as Hudson/Nec intended it originally it was only the TenNoKoe huey that could permanently store it, If you change the battery it can probably hold memory from anything from a year to several years but if it's still original you have to boot up your machine once a week, as it only holds memory from like a day to a couple weeks. The TNK2 can be powered with having a machine on I think and you can then change the two AA batteries, if you just change them without having the machine on I think it looses all memory, can't say for sure but very probable.
The original batteries had a Hudson Logo... Pretty neat... exp date like 89-92. (BEEPOWER R6P/SUM-3) Hudson just called them C8501.
Should also be noted that when this flashable memory was developed it was brand new and did not allow that many writes until error start appearing and became unreadable after awhile.
On the IFU you can access the "RAM" menu by pressing select when having a system card in.
TG16 owners might try the same thing, you must have a TG16, Dockingstation, TGCD and a system card in, I'v never tried it so I don't know but someone of you out there might confirm a menu there when pressing Select.