I have Sony home theater, SR4W, it serve me very well till now. It loses signals to Subwoofer sometime. Woofer connection is good, but sometime it work and then down. Any clue
The external connections may be good, what about the internal connections?.
Subs typically have a lot of vibration. Can you test the sub on a different channel?.
Intermittent issues are invariably loose connections. Either thermal or cracked solder joints.
It could also be electrolytic capacitors in the subs power supply.
Re-solder the bad connections. Often the solder joints between the external connectors to the subwoofer and the internal pcb are bad (dry or cold solder joints). Often caused by mechanical stress. It suffices then to re-solder these connections.
Yes, it’s an easy job. The difficult (time consuming) part is disassembling and reassembling the unit. Any good technician will have the know how and experience to do it.