Hi AK Was visiting my parents this weekend and rummaging around the attic for some carburetor parts when I spotted this SX-450 receiver. It used to run the sound in my dad's office back in the 80s. It was covered in dust and dirt from roof work. My dad still has the manual to it also Anyway, brought it home with me, cleaned it up, and it still works surprisingly. It did have the flickering lights on power on, so I cleaned the power switch as all the threads talk about. I cleaned all pots with D5/F5. It sounds pretty good! DC offset is 3mv on the right channel and 13 on the left. The biggest issue I have with it is woofer excursion and/or popping when turned on and when changing the function switch to or past phono. On power on, the "A" speakers appear to fully bottom out before rebounding as if I push the cones all the way in once. I'm afraid of damage to any speakers hooked up to A. I put it on B now, as some suggest online, but are there bad caps that would cause this? With the function switch, there's no noise going AM to FM. There's a pop going FM to phono and then past phono to Aux. Then a pop when going back to FM through each. I think there may be something wrong with the phono section? Because also when in phono, it is quiet, but if I turn the volume anywhere, only the left speaker crackles/scratchy (and only in phono!). If I turn the balance knob left, everything is silent, but turning the balance knob anywhere right causes noise in the left speaker. ?? Can any of you guide me on how to take care of the popping on power on and when changing functions so I don't damage my speakers? The scratchy phono stuff is less important to me since I don't have a turntable. I just want to know that if I use this thing it won't damage whatever is hooked up to it. Thanks!