Sony SA-WNT5 Subwoofer - no connection, red light flashing

TL;DR - Red light flashes on Sony SA-WNT5 subwoofer whenever wireless link is attempted.

After over-volting my SA-WNT5 Subwoofer (read about it atHow to tell if a Sony device is dual voltage? ), I have replaced the power mount. However, I now find that the sub will not link to the soundbar. When powered on, the red light comes on. When I press the Link button at the back, the light flashes green for a second and then flashes red continuously.

According to the documentation, the red flashing light on this model indicates overheating. However, it doesnt flash unless the sub is trying to link.

If I get the timing right, the sub will actually be discovered by the soundbar…but no sound from the sub and the flashing red light continues.

So…I’m sure either the logic board is fried, or the wireless RX module….but which to replace? Hoping to avoid replacing both…anyone have an idea?