I've sent my LRP IPC SR once, just to have the wires and case replaced (nothing wrong with.) They have good service, but the cost was $30 (with shipping.)
In fact, I'm having that problem with the SR at the current moment. There's either working normally, steering/no throttle, or nothing at all. I found that it was either my receiver, or my receiver plugs that plug into the receiver. Because when I can get it working normally, I "test run" the car on a car stand and "vibrate" the receiver, it will have those problems.
I'm using an XXL RX now, and doesn't have the problems.