If I may quote the "RV Doctor", his advice follows. Unless you are comfortable working with electricity, I wouldn't attempt self troubleshooting. With that said, I quote:
"when troubleshooting any power converter, there are five basic preliminary steps: (1) Verify the proper incoming AC voltage - Be sure the incoming voltage falls between 103 and 130 volts AC. High and low voltage can have a damaging effect, not only on the converter, but other AC components as well. (2) Verify the correct polarity - Reversed polarity or an open hot or neutral wire somewhere in the 120-volt supply system can indeed be harmful to the converter. Always check the polarity and test the GFCI each time you enter a new campground. If it is not correct move to a new site or simply do not plug in the shoreline. Likewise, check the polarity of the DC conductors from the battery. Some components may be damaged if the battery is mis-wired. (3) Eliminate the battery as the culprit - Because of the close association, many times the converter is blamed for battery or other DC system-caused problems. (4) Make sure all electrical connections are clean, dry and tight - Many electrical problems are associated with loose wires and connections. It is a common occurrence because of the jostling most RVs endure during their lifetimes. (5) Analyze the symptoms closely and carefully - Take notes as you go through the process of checking. Follow a systematic approach by first considering the DC system in general. Next, look at the problem area in specifics. Then, consider the components in the sequence. And finally, accurately measure and record the following voltages: * The incoming AC line voltage * The battery voltage in an open circuit test * The output voltage with the converter without the battery in the system * The output voltage with the battery connected Should you need to call a service facility, having the above voltage information handy will provide a starting point to begin troubleshooting. Due to the level of sophistication in today’s power converters, if a problem proves to be interior to the converter, it is recommended that the converter be shipped off for repair. Some well-trained RV service facilities may offer internal converter repairs as a service, but most are probably not fully equipped to handle all possible scenarios. Many components are not field repairable, yet they can be repaired or replaced relatively inexpensively. (Some do have module boards that are easily replaced if necessary.)"
Marshall & Sue
2007 T-195SR (Lucky)
1980 Sunspots (Peanut,Pigpen & Penelope)