How to fix a logitech surround sound system

It is hard to say. The sub-woofer has its own amplifier, although it is supplied the sound data from the main amplifier. It could have a problem with the battery power circuit (Sub-Woofer Amplifier Connector Pin 6, LIGHT GREEN/VIOLET) or it could have a problem with the GROUND circuit (Pin 2, BLACK/LIGHT GREEN) Or it could possibly not be receiving the signal from the main amplifier (Pin 7, BROWN/ORANGE "+"), (Pin 8, RED/BLACK "-"). Or it could be that either the sub-woofer speaker is blown, or the sub-woofer amplifier is defective.
There is also a "High Audio Mute" circuit that connects between the main amplifier and the sub-woofer amplifier.

Check the Woofer for continuity and also with an external amplifier.
if there is no issues then the sub-woofer power amp IC can be faulty.
Check the main voltage to the IC, if not present the power section must be traced for a line break, fusible link.
If there is power , then test for input signal to the IC. If so the IC can be the supect.

Good day sir, Hi, your Philips receiver trouble can be any of the ff:

1. your receiver left fuse is blown, check if it has a user fuse at the back. or
2. your main IC amplifier for the left channel is bad. you need to replace that IC, but check first the wiring of the speakers.
3. Check your receiver left speakers if it is producing a soft hum, to do this turn down the right channel, or adjusting the balance knob to the left, or simply remove the speaker connection of the right channel. place your ears on the left speaker as you adjust the volume up and down, do you hear a soft hum that goes up and down also? If yes the problem is on the source section before main amplification, usually the pre-amplifier stage, If you hear no hum at all. problem with the main left amplifier. The main amplifier is usually a single IC for both left and right channel, OR one IC amplifier for the left and one for the right, in both cases, replace the bad IC.

hello ! there is a short circuit   on power section  need to  be checked and fixed  some Transistor or IC, diode  burnt  .
The fuse gets blown coz power is reversed back  at primary level ,power supply.

good luck 

Hi There.

When you say the 40 Amp fuse blew. Was it your mains battery fuse or was it the fuse on the amplifier? If it was the fuse on the amplifier then you may have hurt the amplifier. The Kenwood KAC-8101D is a 1000 Watt monoblock amplifier. Therefore if you say that 1 of your woofers is not playing, then it is almost certainly blown if you are sure it is connected correctly. Try disconnecting it and only running the woofer that tries to play. If this woofer is still working correctly, you will notice a drastic drop if the sound of your bass. The reason for this is because you have changed the impedance load on your amplifier due to the fact that the other woofer is not working. Have your working woofer checked and replace the faulty woofer then you should be banging again.

Hope this helps!!