IF your converter is anything like mine, you don't need to pull it
out of the wall yet.
You can remove the front and gain access to the connections.
It sounds like you have a loose connection somewhere.
At this point I do not think your converter is bad.
Start by tugging on the wires at the screws next to the fuses
in your converter fuse area.
Tighten every screw connection you can see in there.
If that does not fix anything it's time to start
pulling light fixtures off the wall.
There is a loose wire nut or crimp connection somewhere.
It could be behind any light fixture that's not working.
It's totally up to you whether you take it back for warranty
or try it yourself.
In my case, my dealer was a full 200 mile drive away and I have
electrical experience so I do all my own troubleshooting.
Dan & Rita D
2004 5.3L Silverado 1500 ext. cab 2WD
1999 Suzuki Intruder Motorcycle
Blue Ox WD hitch, AirLift load levelers
Camping days 2010-53, 2011-47, 2012-41,
2013-41, 2014-31, 2015-40, 2016-38