Sites like ManualsLib or ManualsOnline host user-uploaded PDFs. Search for "N15235" directly. Warning: Never run a "driver updater" software from these sites. Only view the PDF.
Foxconn no longer hosts direct downloads for many legacy products, but the community and third-party archives maintain copies. Here is the recommended approach to find a safe, virus-free PDF: Foxconn N15235 Motherboard Manual Pdf
Since I cannot know exactly which revision you have, here are the direct links to the manuals for the most common boards that carry that N15235 marking. Option B: If your board looks like this
Option A: If your board looks like this (DDR3, LGA 775): It is likely the Foxconn G41MXE Series. Option C: If you are still unsure: You
Option B: If your board looks like this (DDR2, LGA 775): It is likely the Foxconn G31MV Series.
Option C: If you are still unsure: You can use a system information tool like CPU-Z (free software). Open it and click the "Mainboard" tab. It will tell you the exact Model Name. Once you have that name, you can find the PDF on the official Foxconn Support Site.