GA-Z97X-Gaming G1 WIFI-BK - Front mic jack not working

[Duncan]

Cooler Master Haf Stacker 935
GA-Z97X-Gaming G1 WIFI-BK (rev. 1.0) running F3 Bios (as shipped)
Intel® Core™ i7-4790K Processor (running stock fan while building)
Corsair Vengeance — 16GB Dual Channel DDR3 Memory Kit (CMZ16GX3M2A2133C10)
2 x 256Gb Samsung 850 PRO SSDs - Raid 0 Boot
Microsoft Windows 7 Ultimate 64 Bit
4 x Seagate ST2000DM001 2TB SATA III - Raid 5 Data
Asus Blu-Ray Drive
Coolermaster Vanguard V1200W PSU 80+ Platinum Full Modular

Dell P2311H - 23" 1920 x 1080 (using motherboard DVI output)

I've been building the above system over the weekend. Unfortunately the motherboard appears faulty as the front mic jack doesn’t work when connected to the motherboard F_AUDIO header using either the HD or AC'97 connector. I have tested the front mic jack using an alternate motherboard, that I know works, and I have tested the motherboard on an alternate front mic jack and it still doesn't work. I've tested the motherboard mic jack directly and that works perfectly. All my drivers are up to date

I'm about to contact the supplier to arrange an RMA but I’m hoping that posting here brings to light something (probably obvious) that I have missed? Any and all help is very much appreciated.

Duncan

[autotech]

Strange I have the Gaming G1 without wifi and mine does the same thing. Seems strange both ours do this.  So I opened realtek manager and plugged them in and hit test they play sound

Now they work on everything. The first time I tried and didn't work so I turned speakers off and plugged them in tested thru sound center and now it picks them up with speakers on