Well, after four years the convertor finally died. I missed my recorded TV from the DVR. I discovered the inverter had shut down due to low voltage. I use my inverter to supply power to the DVR (otherwise it loses memory every time the power goes out). It had been cloudy, but not THAT cloudy! My solar is just a backup to the converter... so what's up? No hum, and no voltage output. Checked with the local RV dealer. He wanted about $500 for a replacement unit. That's about matches my repair deductible ... so I looked for an alternative. Online, I found an exact replacement for $181! I had to wait a week for it to arrive. Informed my wife she wouldn't be watching TV ALL night She was so thrilled with the news. We got by on solar for a week. Got the replacement unit installed. Works fine ! Wife's happy again! Thank goodness for online availability and a patient wife!