ok guys i could use a little help with a 4300 that i have..it has absolutely no audio coming from either the stock speaker or the ext. jack..radio is modulating but has no talkback or receive audio from either speaker jack..i can inject a signal from my generator and watch the radio meter come up as i raise the voltage but nothing from speakers..changed audio chip and checked a few caps around the chip area..not the speaker jack either as i was trying to raise the level of the talkback when failure occurred.everything was working fine on radio just had very little talkback volume..after install of resistor to bump up talkback i didn't have any receive volume or talkback audio..as stated earlier the radio is transmitting and receiving just have nothing from speaker jacks not even a hiss..any suggestions or if anyone has had a similar problem or remedy for it ,i would thank you very much..