It appears to be a battery problem. If the battery won't charge, it won't start. Possibly the batteries fail because we only use it a few times a year when traveling and the charge gets too weak.
You may want to try replacing the 12v charger cord. We thought my wife's wouldn't hold a charge but when I hooked it up to the 120v charger it was fine. We got a replacement 12v charger cord for under $10 on Amazon, I think.
