Hello,

so I have 07 c280 4matic with Harmon Kardon amp. I bought an aftermarket android radio to install in my car. I am aware that my car needs fiber optic box in order for me to use the stock amp. I bought all the necessary stuff including the fiber optic box and unfortunately the radio came with three different plugs to attach to the stock plug. Well I must have picked the wrong plug caused something to burn out on the oem side where now I don’t have any sound coming from the oem speakers even with the oem radio back in. I had the amp checked from Becker and it’s fine. I checked all the fuses and thought 2 that were blown when fixed would fix my no sound issue. What’s weird is that the volume +\- and the phone buttons on the steering seem to be working fine except that the radio doesn’t show volume going up/down on the radio.. anyone know what the hell i burnt out? Relay? Fuse? Any help would be great