Aragon 4004 power light on but no sound

Thank you all for your discussion. I have sent it to a service center. Hope it will be solved at reasonable cost.

I never cycle an amp off and on without waiting at least 1
minute. I seem to recall Aragon or perhaps another warning
not to do this.

If you get it running again, do NOT power it off...

-RW-

The amp does have a relay that mutes the output at initial turn-on for 3-5 seconds. It might be if you are turning it off then right back on, the relay hasn't had time to reset. Try leaving it off for a few minutes, then turning it back on.

Also, like Partial stated, it could be a faulty power switch and/or relay itself that is causing the problem.

Thanks for replies.
After a night, the amp worked again. But as soon I turned it off and on, I had no sound.
i ll check the rail fuses as you adviced.
Thanks again.

Yes, check the rail fuses. But since it appears that both channels are dead it might be a fuse (or problem - faulty power switch?) related to the power supply. More likely that than two (or perhaps four) rail fuses blowing simultaneously.

Check the internal speaker line fuses.