Navigation Plus RNS-D Code Not Recognised

[RSPowerUK]

Hi to all,

I recently purchased a used Nav Plus RNS-D off Ebay - Part number 4B0035192M and I have had the safe code confirmed by a couple of different online radio code providers.

The code is not working after repeated attempts and the power to the safe pin etc all.looks fine. Ignition is on when its reset the radio and accepting the code. Just keeps saying wrong code.

Could a faulty unit mean the code is correct but just not working or is just the online code providers are wrong?

I've called Audi and they say I need to bring the car and radio to them so they can fix it.

Does anyone have any ideas what I can do without taking to Audi?

Cheers in advance