2013 Moomba Mobias Radio won’t turn on

Our boat has a Sony Marine radio (see pic) with two tower speakers and a sub woofer. Since I’ve owned the boat to turn on the stereo all I had to do was throw the dash switch on. Over the winter the shop changed out our battery and when I got it back on the water the stereo will no longer turn on when I throw the dash switch. The red light on the dash switch comes on, so I know that is getting power, but the stereo doesn’t come on nor does the stereo controller in front of the throttle on the drivers side. I checked the stereo breaker switch under the dash (one of the reusable breaker types) and all the breakers I could find leading to the inverters, but they were all fine. I don’t have a sensitive enough volt meter to check if there’s power coming into the back of the stereo so can’t figure out if there’s no power getting there or if I’m an idiot and there’s some sort of on switch/button I need to push on the stereo after it reset (all I could find was an off switch). Appreciate any and all ideas. Thanks!

Sounds like a cable got left off the battery.