*THE ANSWER TO ALL YOUR PROBLEMS* (i hope)
Ok the problem is PURE hardware origin,
moreover NOT some kind of BIOS or Power Management Unit mess,
it's just a small trigger inside Headphones Jack.
LOOK on this image i created of a mac book pro side
(whatever the other jacks on other macs are the same):
Click to enlarge (from ImageShack, don't worry it's safe):
legend:
1) Headphones Analogical OUTPUT trigger.
2) LED for Digital (Optical) OUTPUT.
3) Digital output trigger sphere.
4) just a paperclip.
Description
The problem origin is from the headphone_set pin itself.
The system has 3 states of Sound output:
-internal speaker,
-analogical headphones output,
-and in the end Digital output
when you listening to internal audio speakers BOTH triggers (1 and 3 on image) are pulled out (toward the center axis of headphone jack hole).
now you plug your headphones inside: first the trigger (1) nearly at 1/3 of depth is plugged down and the system goes to state 2- analogical headphones.
as you push headphones pin deeper inside hole it reaches the second trigger (3) at 3/4 of depth (and on left side) of digital output.
This makes the system go to stage 3-Digital Output (if the jack you plugged is Optical receiver), if not, it still Starts up the LED (2), but the output remains on stage 2-analogical.
the problem of that MOST of yours internal speakers don't work anymore
*IS THE TRIGGER (3)*
it's seems like a small sphere pushed out with force of a small sling, which weakening process is up since you plugging and unplugging the headphone jack.
so the problem is:
When you pull OUT the headphone set pin, the Trigger (1) disables going natural position (Unlocking the first lock to Internal speakers functionality)
BUT the trigger (3) seems to be still pulled inside and stuck there (maybe cuz of sling), and preventing the Second Lock of internal speakers to open.
+*That's why if you go on Sound Setting Panel you still see the Digital Output and the "RED LIGHT" from the headphones jack. And most important, System internal speakers MUTED.*+
SOLUTION:
I used a paperclip (like (4) ) and tickled the trigger (3) so to make it come out again (unlocking the second lock on internal speaker) and System sound is Back again.
*Solution is Rough !!!* REMEMBER this WON'T make the trigger (3) internal sling that pulls out the small sphere stronger back as it was brand new.
just be cool, life is short smile more.
iBlackLotus.
Message was edited by: iBlackLotus
