I don't have a 2235 manual on hand but this sounds very similar to my case with the T948 main inverter transformer (120-1348-03) used in the 2213A that had failed, in my case on a scope I fixed about 10 years ago. Once I replaced that transformer with one taken from a scrap board, everything came back to life. So these sometimes do indeed fail, although apparently not very often. I never did any testing to the failed one, so no idea what really went wrong. Wish I could offer more insight but that's it for now.
