Wr703n Soldered Serial line, might have burned something

Wr703n Soldered Serial line, might have burned something

I flashed the router with OpenWRT and it worked fine.
Then I opened it to wire a serial line.(like this:
http://dangerousprototypes.com/2013/07/14/use-the-tp-link-tl-wr703n-to-send-arduino-sensor-data/)
After I was done, I verified that I didn't put solder on the components
and measured the resistence between tx/rx and power/ground. TX/Rx are
around .6 and power/ground around .95(1 being full resistance). When I
power the router, the status led stays on and even after I wait and click
on the reset button, the led doesn't blink. According to this:
http://wiki.openwrt.org/toh/tp-link/tl-wr703n#failsafe.mode, the led
should blink. It also seems to be fainter than before I opened the case.
The router isn't recognized anymore by Ethernet nor does it provide an
access point. What might have been destroyed and how can I prevent this
next time?