I know this is an old post but it is the only one I found that actually showed a fix for the issue with the LG LHB975.
Mine stopped synching about 6 months after I got it. Sent it for repairs and it worked for about 3 months. Since that time it has not worked. Neither the subwoofer or the rear receiver showed anything but red after trying to remate. Neither set of speakers or subwoofer make any sound at all. The front speakers and center speaker work fine.
Found this post and tried swapping the card from the rears into the subwoofer, made no difference. Figured both cards were shot.
Ordered two new cards from Sears, and they only sent me one. Backordered the other.
I have tried every possible combination and have no luck at all. Figured I would try to just get the
subwoofer to work by itself, swapping each card into it one at a time and remating per instructions. I also tried shutting off the main unit, holding the power button for 30 seconds, and plugging it back in before each remate attempt.
Here are my results:
1. The card that was in the rear receiver and has never been changed shows FW version 126.96.36.199
2. The card that had been replaced by LG in the subwoofer shows FW version 188.8.131.52
3. The new card from Sears says FW version 184.108.40.206
If I put the first card into the subwoofer, and go through the entire hard reset and remate procedure,
when I plug the subwoofer in there is no light whatsoever.
If I put the second card into the subowwofer, hard reset and remate, the light flashes blue like ten times
and then turns and stays red.
If I put the new card in the subwoofer, reset and remate, the light continually flashes red/blue ten times,
glows blue for a moment, then goes throught this cycle again indefinitely.
At no time do I get any sound from the subwoofer. No matter what I do.
I assume that since the subwoofer won't even light up with the card from the rear speakers (the old one) that it means that card is bad, but if that was true wouldn't the subwoofer had still had sound with the card LG had put in it. Or if they don't synch does it turn off the subwoofer and the rear speakers?
Any ideas what is wrong here? I also ordered a replacement transmitter today in case that is why neither set of speakers will work, but won't have that or the backordered card for a while.
Does anyone know how to open up the wireless receiver for the rear speakers? I undid the screws in the midline and one of the side screws in back, but 2 edges of the box won't open.