My beloved Logitech Z623 wasn’t working properly recently, the satellite speakers worked fine but the subwoofer wouldn’t output anything, it would output some bass sometimes for few seconds then it would go mute. I outright expected the worst and was disappointed that just after 2 years of buying them they stopped working, one of the main reasons why I choose Logitech Z623 over Hi-Fi Music Systems was the belief that these basic speaker system will be much more durable than the Hi-Fi systems which have in-built amplifiers, cassette player, cd player, displays, etc. The way I saw it was that Hi-Fi systems had too many components that could malfunction after a period of time whereas in a 2.1 speaker system there is probably only a single electrical board and then speakers which clearly are much more durable.
So googled for some troubleshooting tips and there were some scary answers saying the electrical board in the subwoofer might have cracked under heat and replacing the board is the only way to fix it. There were the obvious solutions too, like checking if the cables are connected properly. Checking the cables was obviously the first thing I did but I didn’t do a thorough check, just made sure everything was connected. Since the subwoofer was working fine a day before and I hadn’t moved the subwoofer or cables, so the cable issue was ticked off outright.
Finally, I was considering replacing the speaker with an affordable F&D speaker but decided to give the cables connected to the subwoofer a final check, powered on the speakers connected to Cowon C2 player and played some nice jazz music, as expected bass was missing, checked all the cables, everything was connected properly, decided to remove the D-Sub cable from the subwoofer which comes from the right satellite speaker, so removed the D-Sub cable from the subwoofer and re-connected it but without tightening the screws and what do you know, IT’S ALIVE, the subwoofer started pumping bass again. So it turned out that the D-Sub cable was the issue. As I said, I hadn’t moved the subwoofer or the wires to effect it, I think the problem happened because it’s monsoon season here, so may be moisture must have effected the electrical board in the subwoofer. Even after the issue was resolved, the very next day the subwoofer again wasn’t working and had to remove and re-plug the D-Sub cable to make it work, so if you’re facing similar problem with any subwoofer just try this solution and see if it works.
After testing the above method for few more days I noticed that if I switched off the subwoofer for few hours and then if I powered it on, the same issue crops up. So for the last couple of days I have kept the speaker powered on and now the subwoofer works normally. So basically to fix the subwoofer issue – 1) fiddle with the d-sub connection till the subwoofer starts to pump bass properly. 2) Once the subwoofer works properly keep the speakers powered on all the time.