Open it up and start from the finals and inject noise with a screwdriver tip at various points (always use a plastic handled screwdriver), and work your way back until you no longer hear a buzz when you are contacting a point that should make noise, and start checking components in that area first, it may be a bad solder joint, it may be an open capacitor, or burned out resistor. If those check out, then look at your active components.
If there is nothing at when you try the noise injection, look at the power supply, and the transformers in the output stage(s). Since both went channels failed at the same time, I would suspect a poor solder joint in the power supply, failed resistor- those that look like a small piece of concrete are actually fuses too, and they may have burned out. It also never hurts to double check the power cord too.
: I have an old school marantz 2245 reciever when i first got it about a year ago it worked beatifully but then one day it justed stoped working i replaced all the fuses and tried diff. inputs but still nothing comes out if you have any info at all please e-mail me at Kotel69@aol.com
: Thank you very much
: DAVE