My combo modem/router is going after only a couple of years. The AT&T tech who was here said this is typical. I do have a good quality UPS, so I’m pretty sure that is not the issue. And, the unit is well ventilated. (I don’t need wireless.)
A bit of search on modem/router longevity gave me nothing useful. Is it so hard to make a modem/router that is going to last 5 or 10 years? It’s not like there are any moving parts.
If anyone has a brand they recommend, I would love to hear about it. AFAIK, the big companies (Toshiba, LinkSys) as well as AT&T (my connection service) all start failing and have to be replaced ever couple of years.