Your router may be dying if you are experiencing repeated Internet connection failures. If your Internet connection isn't working properly, your ISP may test the DSL or cable modem to determine if the problem is with their equipment. If your ISP assures you that its equipment is functioning as it is supposed to, you can determine if your router is dying and needs to be replaced.
Loss of Power
Nearly all routers have status lights to indicate power, connectivity and network activity. Your router may be dying if it randomly loses power or if it does not power on at all. This usually indicates a failing power supply. If the router does not power on, be sure to check the electrical outlet to see if other devices receive power to determine if the problem lies with the router or the electrical outlet.
Your router may be dying if it drops the connections randomly but consistently. This is especially true of wireless routers. If you are using a wired Ethernet connection, try replacing the cable to determine if the problem is with the cable or the router. If you are using a wireless connection, try moving the wireless device closer to the router to see if the connection is dropping due to interference. If the connection still drops, the router may be faulty.
A randomly-rebooting router usually means the router is dying. Routers are essentially small computer systems with a CPU, RAM and storage. Routers run small operating systems. A rebooting router is similar in concept to a Windows "blue screen of death." A router that reboots constantly indicates a hardware problem and needs to be replaced.
Routers store their internal configurations on flash memory. The router is dying and needs to be replaced if it loses its configuration each time upon power cycling the router and returns to the default factory configuration. This indicates a problem with the internal flash memory and there is no way to recover from this except to replace the router.