SOLVED Help needed with positioning transistor on BM 900

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drfresh Posted: Sat, Aug 14 2021 11:01 AM

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Hi all

OK - consulting some old books on electronics and very carefully studying the scematics helped me out. I don't know how I can mark the post as solved other than by words. 

Now I really have messed up and need some help!

I was cleaning my perfectly working BM900 and had the circuit of of the wooden box. Now the wires for the built in speakers are quite short and somehow the sound in the right speaker suddenly disappeared. Now I found that the wires are connected to a plug that fits in a socket. I thus wanted to pull out the plug and see if it was one of the wires that needed soldering. But doing so the socket broke. See below:

I then wanted to try and see on the back of this socket id I could just solder the speaker wires on the back. I then needed to "flip" the two circuits mounted on a metal frame. I didn't see this little fellow: 

and when I flipped the metal frame the transistor was "plugged" out of the circuit:

Before I try to fix the wires for the speakers I need to solder tre transistor back in place (and hope it still works. But how should I orient tre three legs? I see a little red dot on the transistor that I guess is the key.

But I really need help on this one in the first place. Later I probably need help as well with the wires for the speakers.

Thanks in advance for any help!