The electricity supplied to electronics
I have an electronic device that has an external transformer for a power source (i.e. a power block). If it’s relevant the electronic device is a cordless phone. One day the phone died. I determined the phone itself was fine, it was the power adaptor that died. I used another power adaptor that was close which leads to my question. The original power adaptor was 9V 800mAmps. The replacement is 9V 1000mAmps. The phone is working now but will this damage the phone over time? Is the device smart enough to only accept what it needs despite the amperage supplied? If it was 9V 2000mAmps, would that be bad?
Also what about the voltage? Had I used a 12V or 18V power adaptor would that fry the electronic device, is the device smart enough to use 9V of potential even though 12V is supplied.