Start from scratch
Like most electronics, when things just aren't working right, it's time to start from scratch. When I got my new 9303 a few weeks ago, I knew absolutely nothing about it. Followed the instructions in the manual and it worked just like it said it would.
Your radio came with a three wire switch. On one side of it you have two sets of wires and on the other side you have one set. Connect the one set side to the receiver. On the two set side, plug one into your battery and the other set to your binding plug. Make sure the remote receiver is plugged in, too.
When you turn on the switch, the receiver will be in the binding mode and the lights will flash. While pushing the bind button on the back of the transmitter, turn on the transmitter. The lights should stop blinking on the receiver and go solid.
It's all on page G-19 of your manual.
Once you get all your parameters set up for your aircraft, follow the instructions on page G-21 for your R921 receiver to set up the Fail-Safe.
BTW, I'm not trying to 'take away' anything the other responders said. Just thought you might want to take a step back and start all over, following exactly what the manual says to do. Some manuals suck when it comes to the instructions, but in this case, it's pretty straight forward.
I keep on thinking, but nothing's happening. Knuk, Knuk, Knuk