For OEM systems they rarely/never list the front panel connections in the manual that comes with it - it's more of a "quick start" guide than it is a full-blown manual.
Trial & error will be your friend here, I'm afraid.
What are you trying to achieve with sourcing the manual?
That;s a motherboard model number, AFAIK. You'll have more luck with the specific name of the system, I would imagine (should be on a sticker somewhere).
For OEM systems they rarely/never list the front panel connections in the manual that comes with it - it's more of a "quick start" guide than it is a full-blown manual.
Trial & error will be your friend here, I'm afraid.