Motorola RDU4100 Channels Not Working

[ylink]

Hi, Im new to the forum but Im hoping someone can help. We are using RDU4100 radios. I have one unit that when you turn the channel knob, it doesnt announce the correct channel or at all for some knob turns. Its skipping channels and doesnt even go in order.

Knob on 1 - Announces Channel 1 - Correct
Knob on 2 - Announces Channel 2 - Correct
Knob on 3 - No Announcement, nothing happens - this is my main problem and I need for it to go to Channel 3
Knob on 4 - Announces Channel 1 - should be channel 4
Knob on 5 - Announces Channel 8 - should be channel 5
Knob on 6 - Announces Channel 7 - should be channel 6
Knob on 7 - No Announcement, nothing happens, should be channel 7
Knob on 8 - Announces Channel 8 - Correct
Knob on 9 - Announces Channel 9 - Correct

I have the CPS cable and have been trying to ticket around in the CPS software, but I dont see anything out of place. I took a known working radio and checked the settings and they appear to be the same for this non-working radio. Does anyone have any suggestions on how I can get the channels aligned properly and getting on each channel?

 

[AM909]

Did you actually re-program in the bad radio using the codeplug from the known working one? Probably bad channel switch/encoder if it behaves differently than another radio when both have the same program. The part may or may not be available – I don't see a manual.

 

[ylink]

Im fairly new to diagnosing and fixing radios. I have not tried to reprogram it, not sure what a codeplug is to be honest. I spoke with Motorola support and they said its most likely a defective board. Im assuming the channel switch encoder is soldered onto the board? Im not looking to do any heavy work on this, thought maybe I could do something with programming to fix it. Anything I should try first before calling it done?