You indicated ALL power except microwave was out. It definitely sounds like you have no DC power. Have you checked other AC powered items? Air conditioning, refrigerator on AC, televisions, AC outlets? Assuming those still work your problem will be isolated to DC. If those don't work, or some of them don't work, you probably have a problem with AC power either feeding the RV or within the RV.
If it is 50A service, it's entirely possible that one leg of the 50A service has become disabled and thus is not powering your power converter and other items. If it is 30A service, there is only one leg, so this wouldn't apply. First thing I would check is to verify the power going to the RV is all OK. Some surge suppressors have indicator lights to show power and "correct" connection. This is a very basic indication, but its a start. If you don't have a surge suppressor or the one you have doesn't have indicators you can check with a voltmeter if you have one and are comfortable using it.
Once you've verified power being supplied to the RV is good, start checking inside the RV. Verify the circuit breakers in the load center are all on and not tripped. Verify voltage is being supplied to the converter. In a lot of modern RVs the converter simply plugs into an outlet on the back of the load center or a dedicated outlet run from the load center. You can verify power using a voltmeter or just plug something else into that outlet and see if it works. If the converter is getting power, then the troubleshooting gets a little more complicated.
Most modern power converters will happily supply clean DC voltage, when powered from the AC line, with or without batteries attached. Many older converters used the batteries as kind of a filter to stabilize the output. A bad battery (shorted cells) or excessive load could have blown a fuse or the converter might have taken a power surge or could have just failed for another random reason. Once the converter fails, it will no longer keep the batteries charged and even sitting "idle" there are enough parasitic loads (gas/co alarms and similar) to drain the batteries in as little as a couple of days even if they were good.
Now that the batteries have sat for some time in completely discharged state, they will likely need to be replaced, but you might try charging them.
The converters on most RVs make lousy "float" chargers. Most of them will overcharge the batteries if left plugged in constantly. Modern converters are better than they used to be, but still have little "intelligence". For storage, I use a dedicated float charger. Mine is battery tender brand, but there are many. I recently installed a battery disconnect, but before that I still used the battery tender. When I put the TT in storage, I leave the AC to the trailer disconnected and attach the battery tender directly to the batteries. Before installing the disconnect, this just meant that things like the CO alarm stayed on, but the battery charger still just kept the batteries topped off as needed. Chargers not specifically designed to be maintainers, like the converter in your TT, will over time end up over charging the batteries. Another benefit to not having the RV hooked up to AC is that there is almost no chance of lightning and/or surge damage to the AC appliances in your RV, and if you have a battery disconnect, even the DC side of your RV is protected.
