thanks for replying my post!

i did as you says. but i couldn't find the fuse door. there's a
little square plastic cover door in the back with a screw besides it.
i unscrew it and couldn't take the cover off. it probably tightened to
the body of the stereo.

i tried to take the whole thing apart but i don't have all the screw
drivers, there's some screws need extra long shafted screwdrivers to
take it off.

i had the problem occured after a thunderstorm, fuse burnt-out seems
like a most-probable cause.

this unit is also battery-powered. do you think it'll work if i
install the battery? i'll try it anyway, man, 8 D-sized batteries,
what a monster