I need a schematic for a uniden MC 480

How do you know that the radio does not transmit? The batteries need to be fully charged, or new to transmit. The radio is old, and the cost to repair it may be close to how much a new CB radio is.

Good luck.

There is no "linking" of these radios. they simply have the ability to have silent receivers until a digital or subaudible tone is received that turns the audio on allowing you to hear the transmitted signal, this allows you to set the radio to only hear the correct transmitted signal...
http://www.manualslib.com/manual/733780/Uniden-Pmr845-2ck.html?page=15#manual

Need more information. Which channels don't work? Not all channels are authorized. Typically, the radio will not fail in such a way to allow some channels to work but not others.

Possible programming problem. Your receive frequency may not be set the same as your transmit frequency, or your PL code may be set differently between the radios. Check your programming.

Best regards.

Just to clarify something, you say that your hand-held VHF can receive a clear transmission from the Uniden, now which of the radios are buzzing, the Uniden or the HH?. If it's the hand-held buzzing try transmitting on the low watt on the Uniden, get some distance from the radio, because if the hand-held are to close to the on the Uniden on high watt you will get a buzzing, the signal are overpowering the receiver of the hand-held, try getting the minimum of 30 feet away. Good luck.

Hello there:
You can find a local uniden dealer using google www.uniden.com and then you will see find a authorized dealer than all you have to do is call them ok

You may have a sub-channel/privacy channel activated. Unless the person/s you are trying to talk to have the same channel and code set they will not be able to hear you. Check your manual for specific instructions on how to reset it to the default.

While your MC610 was a great radio for it's time. the Oceanus is an excellent choice to replace your MC610. Unforunately you would be looking at about a $100.00 repair bill to repair your MC610. for just a little more you get a new radio and the new radio will have a warranty.

While there might be a multitude of answers to this question. The first would be the radio is in need of repair, or not programmed correctly.