Debricking a Netgear D6200

I have a Netgear D6200 WiFi DSL Modem Router (http://www.netgear.com/home/products/networking/dsl-modems-routers/d6200...)

After a power surge, the router has stoped working and now shows a continuously flashing amber light when powered on. 

I have tried a factory reset and a 30/30/30 reset and neither has made a difference. I have also tried to tftp into the router, but the router is unpingable when connected to a computer over ethernet (and with the computer set to a static IP on the router's default subnet). 

From Googling and reading through various fora it seems a JTAG/serial based means of trying to recover the router might be the only options available. However I haven't found any instructions or a HOWTO/guide that I feel confident enough to follow, partly because I am new to hardware recovery methods and also because instructions specific to the D6200 do not seem to be available, and I don't know enough (yet) to know what can be safely extrapolated from what works for other routers. 

Consequently, I'd be grateful for any pointers or advice on whether my router is still recoverable (or how to determine if it is or not)  and how to proceed if yes.

Any suitable-for-newbies pointers to serial or JTAG recovery (and what they are and how they're different etc) would be particularly appreciated, and any instructions/advice for a D6200 even more  so...

Thanks in advance!

(And apologies if this is the wrong forum; I assumed the R6200 was close enough to a D6200 that it wouldn't be a problem...)