As per my earlier post, you haven't elaborated on "how" you tested night mode and concluded that it wasn't working other than restating that the IR illuminator was not visibly active -- the steps you took to arrive at the end result are equally as important as the end result itself. Also, firmware can get corrupted, as I've personally observed this happen. I'm only trying to help, and without additional feedback from your end, there's not much more that I can offer in the way of support.
Presuming the purchase date you previously provided is accurate, the only thing I can say with absolute certainty is that the warranty for your DCS-932L has expired, precluding official channel replacement/repair options.