Freedom Heart 15 not charging

[jeb]

We've owned our RV since 2004, and the Freedom Heart 15 has always been great. Never had an issue with it. I leave it plugged in our RV building with a timer that supplies power to the RV for about 3 hours each day. Recently, the power cord came loose in the compartment and I didn't notice until the 3 - 12v house batteries were dead. Hated to see them take that abuse, but figured not a huge deal, plug the RV in and away we'd go.

Not so much. Ever since then, the charger has not kicked on. It sees the battery state on the remote panel in the RV and shows that it sees the AC. I've run through the setup process and all the steps work. But it won't charge or invert. The lights on the remote will come on when the buttons are pushed, but nothing happens.

Read the troubleshooting steps in the manuals, and tried unplugging the cord from the remote for a while. No change. Called Freedom/Xantrex and they suggested removing the AC and DC power to the charger for at least 2 hours. Tried 3 hours and 3 days. No joy. In the meantime, I charged the house batteries with an automotive charger. All DC circuits work. All the AC ones do also, if the RV is plugged in or on generator power. Checked all the AC and DC breakers, none tripped.

Is there anything inside of this unit I can check? I thought I'd read there might be some fuses in there? I'm very comfortable and competent with electronics. Just does not make sense to me why anything would have blown from the batteries running down, so hoping there is a fix for it.