HELP!!! - OA21 not singing

Hi,
Just moved my setup to Shanghai and after 1 day of setup and cable fixing, turned on all my equipment = no sound.............

After some trouble shooting, OA21s is the proble.
(I tested my Cd player, interconnect and speaker cables, all sing well on my AV setup).

I suspect something has blown in the OA21 as I'm in a place famous for unstable power supply, can someone advise me which part is likely to have blown?
I checked the inside and cannot find any fuse.

The light infont is lited, and there is very faint music through the speakers regardless of volume and line selection when I play.

Thanks in advance for kind advice, I'm quite desperate.