Presario SR1705 Motherboard Front Panel Audio

I have transferred Presario SR1705 (RC410-M Rev: 1.01) to a new case and
assumed it would be straightforward simply connect AC'97 audio cable in the
new case to the JAUDIO1 connector on the motherboard.

Does not work no audio/mute from the front connectors on new case. I removed
the original front audio panel connector from the presario case and tested
it works perfectly.

On closer examination of the JAUDIO1 connector on the motherboard I noticed
pin 7 HP_ON is used on the original front panel audio. Never seen this used
on any previous PC/motherboards.

Wiring Diagram:

Two cables connected on the original front panel audio to JAUDIO1:

cable: 1 2 3 7
cable: 2 5 6 9 10

Is there a simple solution to this or will I have to dremel the orignal
presario front panel connector and construct a metal face panel suitable for
drivebay slot?