I doubt there is anyone here who has a schematic if you weren't able to find it online. Is there a particular problem with one that you're trying to troubleshoot? Many of us who have done a lot of repairing are used to doing so without the luxury of a schematic. A picture of the inside of the thing and a description of the fault is a good start.
Thanks, James, for your gracious offer to help. This is the situation... I was able to repair one, for my best friend. Now, word has gotten out that I might be able to repair these for folks and I will have another one coming, soon.
I am just a hobbyist. I can handle troubleshooting the mains side through to the DC side rectified rails. After that, a schematic sure would help... both for me to follow and for trying to communicate to others, like your kind self, when extra help is needed.
But, yes, even without a schematic, I know that I can get great help from good people right here at the EEVBlog Forum. I make a concerted effort to pay back the help that I have already received, in the past, by replying to folks that have questions that I can answer. One DIY person helping another DIY person makes a better world - more fun, too.
As a final note, I am guessing that you have never seen one of these particular devices, but they are built to the lowest level of quality... Exposed PCB traces, no-name jellybean parts, traces flooded with solder to try to improve their current carrying capability. It all adds up to a high failure rate that strands people that are camping - away from resources and help - trying to make good memories with their families... And these things aren't cheap, at ~$150USD. I'm surprised that they haven't burned down enough campers to bankrupt the company.
Sorry for the rant... I really just meant it as a warning to anyone looking to buy a converter. Stay away from this brand... Even though they are likely the most popular and come as standard equipment in a lot of campers... If you are negotiating to buy a camper, make them swap this thing out for a better brand, as part of "The Deal." All IMHO, of course.