Removing the back panel of the set will let you see whether the supply that has failed is on a separate board or not. If it is, you may be able to remove and replace it yourself.
This site has thousands of boards and assemblies which have been, in part, removed from sets damaged in some way and they do warranty the function of the stuff they sell. If you are lucky, you may find what you need there:
Jimmy's parts

Yes unfortuantely I get this all the time. Unless ya get a "Brand Name" unit and even then, usually they simply do NOT make any spare parts, and what is made is kept "In Country" you could get the board Identification and try to track it down from China, I have indeed done this with some sucess. But no guarantee.
GL