Recently, I did a bit of shuffling around with my devices. My dad wanted wifi he can carry around. So I gave him the Huwaie portable router and my brother got my wall plugged 3G dongle and I was left with my trusty ol' TP-LINK-MR3020. Since I use 3G myself, I decided I would utilise the TP-LINK and so got a NETGEAR dongle without inbuilt wifi instead of a new 3g/4G dongle (cause it was cheaper and won't interfere with TP-LINK's wifi signal). Then in a hurry to get my router to work I flashed it with the upgrade firmware and something went wrong along the way and it bricked the device (3 lights blinking intermittently).
The way to prop it back to life is to to get a serial connection from the device. This involves prying open the device (voids warranty but the concept of warranty itself is mostly useless anyway).
There are two ways to go about this: