Same story, different capacitors. The symptoms were “a loud pop, followed by the smell of burning plastic”. This PC was made by a certain small company that went bankrupt in 2008…it’s a P4 Intel board, so it’s fairly old. Removing the side panel from the case exposed the vented electrolyte:
This failed capacitor was a part of the processors VRM – only one showed to be failed, but where there is one, there are probably more.