I just got a 257 white display non HP model and have a mic question. With the stock mic 6 pin, up and down channel buttons, the channel changing buttons only make it go down not up and the audio is not very good with it but it does talk. I did try adjusting the pot in the mic, no difference. If I hook up a 6 to 4 pin adapter and use a 4 pin stock anything mic the audio is great. This tells me the audio in the radio is fine so there has to be some kind of issue with the mic and the voltage going to it. I tried a good working 6 pin magnum mic from another radio works the same way so it's not the mic itself and I guess voltage is getting to the mic or I would not have any audio at all. Anybody have any ideas??