Chinese Mackie Copy - Active speaker overload LED

[txstrat]

Hey Folks,

hope everyone had a great xmas time.

A friend of mine has an active Speaker cab which he uses as monitor on stage and for playing along music while he's playing drums.
Recently the cab stopped working and the overload led (next to the volume knob) turned on, which it fomerly only did, when he turned the volume too far up.
Now the volume knob doesn't have any effect anymore.
The cab used to have a faint hiss when it was normally operating, which is now completey gone. No Sound at all.

Is there anything I can try to check what might be the culprit without digging too deep into the thing?

Thanks in advance

Matt