Part 432. 3 No LEDs are lit. No sound from one or both speakers. No sound from DVD/ CD-ROM drive. Crackling sound from speakers. The speaker system isn’t turned on. The speaker system is not connected to a power source. You are using the USB port on your laptop computer or PC to power your speaker system and your laptop computer or PC is in sleep mode. The retractable speaker-to-speaker cable is not properly connected. The volume is set too low. You are using an alternate audio source and the sp