What would be some common reasons as to why a DX3R won't bind to an SR3001?

I had to bind a couple of times and I tried binding in different orders to find the bind, I tried the bind the radio first then the rcvr, that didn't work so I went rcvr first then radio and picked up the bind. Sometimes when your not fast enough between the two binds it doesn't want to pick it up so if you can have a buddy bind one of the parts at the some time with you.

Make sure the plugs are in the receiver correctly. Have seen the power plug reversed a surprising number of times, which at least on some receivers causes a blinking light, sorta like a binding blink.

If the receiver model has a bind button, use it, not the bind plug.

Make sure all of the batteries are up, I’ve read reports of radios working fine at lower Voltages, but would not bind at the lower Voltage.

Some have reported binding issues if they hold the transmitter too close to the receiver.

Mine won't bind when under 4v.