M4300-24X Never buy a used one !

Hi

While I can understand your frustration, unfortunately the warranty terms are pretty much clear. While there is a lifetime warranty on these switches, there are some limitations defined in the warranty terms. They clearly state that the switch needs to be purchased via a Netgear authorized seller. Additionnaly the warranty terms contain another blocker: "All NETGEAR warranties [...] are valid only for the period of time the NETGEAR product is owned by the “original purchaser” of the product. The “original purchaser,” for the purposes of this warranty, is the first purchaser of the product from NETGEAR or a NETGEAR authorized reseller. All NETGEAR limited warranties, including lifetime warranties, are not transferable." (see: https://www.netgear.com/about/warranty/)

Since you are not anymore the original (i.e. first) owner of the switch, you don't get the lifetime warranty as well, even if you had the original invoice available.

While these terms are frustrating in your situation, they are not uncommon, compared to other vendors in that segment. I'd even say that Netgear is pretty easy-going. Firmware updates are freely downloadable, original owners get lifetime warranty (I can confirm that it does work), no overcomplicated licensing schemes, and i.e. little-to-no enforcement of vendor branded optics (none that I have experienced yet).

I get it, it sucks, but unless you want to fiddle with a TTL serial port and try getting at least into U-Boot, you'd want to start looking for a proper replacement. - Well, unless you have both time and expertise to do board-level repairs of such devices.