icom sm-30 wiring

[drdr2014]

I've picked an icom sm-30 desk mic that had a modular plug for yaesu 857d. Mic worked fine in that setup.
I want to use it on an Icom 756pro iii, so soldered an 8 pin plug using the following pinout. 1-white, 2-blue, 5-green, 6-black, 7-shield.
I cant get it to key the icom. Do I have it wired wrong or is there some other issue?

[MDYoungblood]

You should have 5 pins hooked up,
pin 1 is microphone audio
pin 7 is the audio negative
pin 2 is 8v
pin 5 is PTT
pin 6 is PTT ground
Pins 3, 4, and 8 are N/C
Sorry but I don't know the color of the wires, you may have the grounds wrong. Check and see if the VOX works.

3's

Greg