Hi There and Welcome to FixYa,
In many amplifiers, this condition that you have can mean that it has either a power supply failure or a blown fuse. The cause of this can most of the time attributed to sudden drop in voltage.
With this, I am strongly recommending that you have this amp checked by a technician to determine if you have :
- Melted fuse
- Or if the fuse holders are still usable
Generally, when the fuse holder melts, the contacts become badly oxidized and the clips lose their tempering - this means that it will continue to overheat and will not function properly, hence, the problem that you're having right now.
I certainly hope this helps,
Thank you for using FixYa.