JBL SUB 140/230 Active Subwoofer continuously resets itself

Hi,

I have a problem where the subwoofer (JBL SUB 140/230) resets itself all the time when plugged in. Resets happen every few seconds or so. When plugged in, subwoofer turns on green light and speaker produces continuous static sound. After a second or so, subwoofer blinks red, speaker makes loud boom (short deep sound) noise and it shuts off. And it does that over and over again.

I have tried to play sound to it but it doesn’t change the situation. I have also tried to connect satellite speakers to the subwoofer and it also doesn’t make any difference.

I assume it is some kind of a problem with the electronics inside. I have checked speaker’s resistance and it is good.

What might be the cause of the issue?