cobra mk2 148gtldx powers up but only get hissing sound,

Hi first post hope some one can point me in the right direction to a fix,
bought a cobra gti dx of ebay, when it arrived it was totally dead, on closer inspection i found a loose solder joint just behind the power point, so i soldered that and it powered up, but when fitting the mic it would go to rx with out pressing the mic key, so re soldered the mic wires as by cobra mic diagram.

When pressing the mike key now it goes to tx red and on release it goes back to rx green but the needle does...

cobra mk2 148gtldx powers up but only get hissing sound,