Hi, the wireless subwoofer of my 3 year old HLB54S dvd home cinema system doesn't work properly. The LED-light on the subwoofer indicates in blue that it's connected to the main unit, however there is only muffled buzzing coming out, instead of proper sound. I have tried disconnecting it and 'remate' function, but it doesn't fix it. Any idea?

SOURCE: I have an LG TV

Hello,
There are two things that I can suggest.
1-Test your optical cables to make sure they a good on a known working source because they are very fragile and break very easily.
2-Try to eliminate the use of optical output from tv to receiver. There may be a problem from the HDMI to optical conversion at the tv. Instead, try running the audio directly from the source to the receiver, and let the tv deal with video input only.
Hope this helps,
Good Luck.

SOURCE: This system has a wireless subwoofer that doesn't

I just called LG Electronics 1-800-243-0000 and this is the solution I got from them. Unplug the main unit from the wall, Hold the ON button for 30 seconds. Plug it back in. That should do the trick. They call this procedure a "Hard System Reset". If this doesn't work, call them back and they will repair or replace accordingly.

SOURCE: hello, I just bought an

We can't make assumptions. Did you set it up in accordance with the manual?

SOURCE: I own a LG HT502SH

No there is no way to replace it not unless you have it repaired by a LG Authorized Dealer/Store.