I’ve been cleaning up my home office and found 2 pretty old smartphones in a box, around 10 years old I’d say. I don’t have any old chargers to check if they still work so I’m unsure what sort of data is on there, if any, or if they still charge up even.
What are the chances I can safely dispose of them at a recycling center, without risk of anyone trying to check into the phone? None of them can have the battery removed so I don’t want to just smash them with a hammer.
If you’re tech savvy, buy a charger, see if the phone works, copy your data from your phone or computer, and try to do a DoD wipe on your phone. If you can’t find any instructions on how to do that on Google, then just try a normal factory reset, sign into a dummy Apple/Google account (with no personal information), then fill up all of the storage with some junk files before recycling. You can repeat this a few times if you really want to.
If it doesn’t work after charging, I’m not sure you can do anything without disassembling the phone. If you manage to do that, take out the battery, store the battery away from heat, and then see if you can find the storage chip (might be called NAND flash; it shouldn’t be anything that says DRAM or RAM). Destroy that chip by drilling a hole through it or cutting it off, then recycle everything else.