If you've got throttle but no steering, I'd hesitate to say that it still works!! But you say it's like that with two different receivers?? If it's not the steering servo that's faulty, then it must be the transmitter...

I am a computer engineer by trade, and I can tell you that if you saw smoke, then whether it works or not, something is seriously wrong with it. Don't use it! You might end up with a WOT runaway. Contact the place where you bought it, say you don't know what happened, see what they say...

By the way...receiver (i before e, except after c, except for the exceptions).