Yamaha YST-SW215 woofer doesn't work any more

So far it works as the way it suppose to be for the entire yesterday, put boards in and screws back because it is hard to monitor the work status, front panel has the light to show.

Was using it as the 2ndary woofer with my main stereo via a Y connector, when it happens, front panel light just went off, can't wake it up not until a full power circle.

Now doing a directly solo connection, will get the V read once it happens again, thx