We have X11DPG-QT motherboards that we are trying to get the audio port to detect the speakers. The cable from the board to the front panel is 3-ft long and was created from the user manual pin-out specifications. The strange things are; 1) the cable works on our motherboards, and 2) if I shorten the cable by 12in (2ft length), the cable works. Is there any special requirement for cable length?
The X11DPG-QT has the HDA set as defaullt, so it requires higher signal integrity. Please keep the cable within 60-cm. If you are using our chassis like CSE-747BTS-R2K20BP, it came with audio header cable.
https://www.supermicro.com/products/system/4U/7049/SYS-7049GP-TRT.cfm