My CR-915 radio won't accept codes. Here is the story.

This weekend, the radio lost power (most likely a loose battery connection that I tightened). I didn't quite remember the code, so I tried my three guesses and then the "off" displayed. Never got around to leaving the key in position I for 2 hours to give it another try.

On monday, car wouldn't start. Had spark, so it was fuel related. The relay just behind the fuses appeared to be clicking as required. Brought to my mechanic and he found the main pump was the problem (not operational even with relays jumped). So pump was replaced along with main fuel pump relay.

Picked up the car yesterday and the radio was displaying "code", so I figured I would just enter the code (which I finally got from the dealer). Unfortunately, it doesn't do anything when I enter the code. No matter what button is pressed, it still always displays "code". So I left the key in position I for over 2 hours and I still have the same results.

One other very unusual thing is that the radio displays "code" even when the radio is turned off by the radio switch and/or when the key is off.

Any clues as to what the problem is or how to fix.

Thanks in advance.