Is my TI-58C hosed?

[Dave Britten]

Yeah, I let it sit unpowered overnight and got the same results this morning.

A bit more weirdness: If I enter LRN mode and start mashing the 1 key to fill program memory, at step 145, it starts saving properly, except for a couple of holes that stay zero. This pattern of ones and zeroes seems to repeat in a cycle of 8 steps. I haven't tested the higher storage register numbers yet. I tried reflowing some of the solder on the Toshiba CMOS RAM chip in the bottom right corner of the board, but that didn't change anything. If there are two RAM chips, I'll have to hunt for the other one and try it again.