I’m glad others have had success sticking things in their jacks to fix this issue—that’s worked for me a couple times but the jack still gets stuck eventually even though I never insert a headphone plug. Finally I came across a real solution at this thread. It’s a very iFixit-style fix, as you should definitely do it with at least a boardview for your computer and only if you’re confident you know what you’re doing, but if done right it’s actually the perfect solution. Since what I propose below is a permanent, hardware-level fix, also look earlier in the thread I linked to find dondavanzo’s software solution. It didn’t work for me, but if it works for you it’s easier, more elegant, and reversible, so worth a shot before going further. The VoodooHDA kext for hackintoshes can force the audio codec to ignore the presence of an optical plug and give you normal behavior switching only between headphones and speakers. By removing a resistor (or inductor, depending on your exact model - my comment over on the...
@josh is correct above that it’s a different procedure for your Mac Pro 1,1. Specifically to answer your question—if you’re still wondering, or for anyone else looking at this—System Integrity Protection was introduced in OS X 10.11 El Capitan. The csrutil command is meaningless for earlier versions, hence your “bad command” error. This can be checked without recovery mode by running csrutil status in Terminal.
@josh is correct above that it’s a different procedure for your Mac Pro 1,1. Specifically to answer your question—if you’re still wondering, or for anyone else looking at this—System Integrity Protection was introduced in OS X 10.11 El Capitan. The
csrutilcommand is meaningless for earlier versions, hence your “bad command” error. This can be checked without recovery mode by runningcsrutil statusin Terminal.