Feels silly to start a new thread about this, so hopefully the rest of you sort by unread and click through all the new threads like I do.
My computer speakers suddenly quit working today. Altec Lansing ACS295 that I purchased from the Dell outlet in Austin in August 1998 for $75. I think they retailed around $150ish but style in computer speakers had changed to those little cubes on a stand making these look obsolete. These speakers have seen some serious ---steaming pile of meadow muffin---. (I did laugh when I saw this style has come back around 22 years later per Amazon)
Obvious culprits such as bad cables and blown fuses were quickly eliminated, so I cracked open the subwoofer which houses the electronics for this set. Everything powers on and the speakers pop when power is applied but no sound. Next step was to reflow solder on the amplifier and input jacks. No change. Then I decided what the hell and started pressing on components while it was powered up to see what happens.
So, if I put my fingertip across the non-inverting input on one of the op amps and a positive terminal on a nearby capacitor, I get sound on one speaker. If I put my fingertip across the inverting input and that same capacitor, I get sound from the other speaker. If I jumper the paired pins to each other, and then to a 100k resistor, and then that capacitor, I can get sound on one or the other speaker without having to sacrifice my finger tip.
While this rig gets sound on one channel, I cannot get any response with the volume/treble/bass controls.
Doing similar experiments on the other op amps does absolutely nothing.
So, I guess I'm looking at 4 options here. 1 is replace that op amp and see if that one component was magically the problem. 2 is replace the subwoofer unit and hope the "new" one works... about $50 on Ebay. Option 3 is strip out the controls from these speakers and wire them up to a new amp (about $45). And option 4 is toss the set and start anew.
I'm hoping one of you has more experience with audio repair....