Hey guys, sorry to bring up yet another cb no transmit problem, I know this has been covered many times, I know because I've read many threads on the same problem but nothing really seems to match my symptoms or cover specific diagnostic steps, and my diagnostic skills are weak at best, but hopefully you guys can help get me in the right direction. The problem radio is an older model Cobra 29 Ltd. The RX seems nice and clear, and PA works well. So far I've tried two known working mics and checked the board for cold solders. There is evidence that work has been done in this thing but I'm not sure what, it looks like a different final at least has been installed, which I've pulled and tested with a multimeter. Based on all the data I found online it tested sat so I reinstalled it. When keyed the Rx/Tx light turns red but I get no deflection on the S-meter. There is an audible "bump" noise that comes from the speaker, then from there zero transmit, I can't even hear a change in the static on an adjacent radio on the same channel. Based on the block diagram and advice gleamed from other threads it seems like IC3 is the first most likely cause but I'm unsure on how to test it. The only diagnostic equipment I have is a multimeter. Any help would be greatly appreciated.