I am selling my bitcoin miner. Is there anything I need to do for security purposes to protect myself before selling it?
I don't think there is anyway the buyer could access my wallet from it. But any thoughts about anything I may not be thinking of would be appreciated.
If the miner is getting it's Internet via a WiFi connection, you should reset that at least. Or have the device reset to factory settings. Otherwise there is no need to do much. If you leave your wallet address in the config, all that could be done is to look into the balance.
Make the buyers life easy by resetting it to factory settings, so he gets a fresh device.