Spinning of your original idea, it could also be that the internal speaker aren't actually connected to node 0x15 but to another node (so the pin config is wrong). Have you tried (in hda_analyzer) the other nodes (0x16, 0x18 and so on) if it could be that the internal speaker is actually connected there instead?
Spinning of your original idea, it could also be that the internal speaker aren't actually connected to node 0x15 but to another node (so the pin config is wrong). Have you tried (in hda_analyzer) the other nodes (0x16, 0x18 and so on) if it could be that the internal speaker is actually connected there instead?