Had it for a few years now. Will type a couple of letters and then stops. Replaced batteries. System preferences says connected to bluetooth. Disconnected and repaired – system confirms connected but does the same thing.
A keyboard with USB connection works fine.
Any system restore trick I can employ?
1st thing to try is to connect it to another device and see if it does the same thing. Can you try it with a phone? I don’t see why it would need to be an Apple device.
Does it fail in all locations? Don’t forget that there are normally loads of other things in the house that use 2.4GHz (apart from Bluetooth) and one of them may be interfering – have you moved your cordless phone base station recently for example?
Junior, did you try the sort of reset that this article goes through?
http://davemeehan.com/technology/how-to-reset-an-apple-wireless-bluetooth-keyboard-mouse-or-trackpad
Not yet will do. What bugs me is the typing 3 letters then stopping. So there is a connection at least initially.