I have a problem with my Netgear R6220 after a power flicker. The router powers on and I see activity on the lan LEDS, however I'm unable to access the router. Additionally, the wifi isn't showing up. I've tried 2 PCs to try and connect to wifi and ethernet with different cables.
I build my own firmware and know you can do an install of openwrt using tftp but I am tryinig not to overwrite my configs. I have a backup but I've made some recent changes and don't have those backed up yet.
What's the best way to try and recover the router without losing everything on it?
Have you unplugged the Netgear power adapter from the wall for >10 seconds or so and then reconnected it?
Have you tried replacing the power adapter in case yours has partially failed (yes, this can happen). According to the user manual, it requires a 12V 1.5A supply. You can use any 12V supply that has current rating of 1.5A or greater.
The power was plugged into the surge port of the UPS so not likely but I can test with a multimeter and yes, it's definitely been unplugged. I'll run tcpdump on my linux box and boot it and see if it tries to do any sort of network communication.
While I obviously can't guarantee that it is the power adapter at fault here...
UPSs and surge protection only goes so far, and the potential for a failure depends on many factors. So even if nothing else was damaged, don't assume that the power adapter was not -- good to test and rule out a failure than to assume it's good and chase your tail.
Further, it's possible that the adapter was marginal/failing, and this power event (or just coincidental timing) happened to be the tipping point for it.
Glad you have one handy, and yes, you should test. But the problem is that you may not be able to see if it is failing under load (for this, you can open the router and probe the main board where the barrel jack connects).
If you have any other 12V 1.5A adapters, IMO it's fastest just to swap and test to rule in/out the power supply failure.
If in doubt, it does not hurt to sysupgrade OpenWrt again (same- or newer versions), as that should cover potential flash corruption (especially NAND, such as your router, is susceptible to this, while it 'should' notice and recover itself (to some extent), that is not a given).
I do have an updated image that I want to upload but not had the chance, that would have been an idea time...but also not, if you get what I mean. I'll plan to do it this weekend.
