hi. i installed http://downloads.openwrt.org/snapshots/ … actory.bin and sysupgrade last week on my tplik mr3420. i delete mount and umount files before to install opkg install mount-utils. But my router not work now. icant ping telnet or ssh to it. i try static ip 192.168.1.1 and dynamic but not work. i dont know the problem.
my idea rootfs mount overly but mount not work in overlysys so it cant mount tmpfs or some...      

1) can i fix it without serial connection?(i try failsafe mode)
2)i  try serial connection. but not work.can you say is it correct?
  i use serial female to female cable
  i soldering a male rs232 with cable and 10k resistor.
  inserted rs232 male pins left to right pins 2=tx 3=rx, 5=grnd  8=vcc.
  insert 10k resistor between rx-vcc and tx-vcc
  plug rss 232 cable between pc-device
  plug cat5 cable between pc-device change ip 192.168.1.27
  install tftpd and change openwrt-ar71xx-generic-tl-mr3420-v1-squashfs-factory.bin as code.bin and browse folder to it.
  plug power to device and try connect to com1 port with putty after to change settings.
  and try to write tpl in 1-5 seconds!

putty is blank and its not work. How you got idea?

thanks much. And sorry to my english...

(Last edited by goatux on 8 Jan 2013, 11:15)

You probably FRIED your router!

TP_IN/TP_OUT serial console signals are 2.7V only, and RS232 is -12V/+12V (well at least -5V/+5V)!!!

This is why you need an adapter, preferably an LVTTL (+3.3V) UART to USB, NOT a simple RS232 cable.

So my guess is that at least the serial console electronic internal buffers are dead, if not worse

   
can i lucky not fired it? can possilty try other cable?
which cable use for this(i use dealextreme or like word free shipping online shopping)
can i use http://dx.com/p/usb-2-0-to-ttl-uart-5-p … lue-152317 direct or must insert 10k resistor.

if it is dead i must buy other cheap usb/wireles/ethernet/openwrt device have userfriendly recovery mod. cany u say any products/devicename/model?

(Last edited by goatux on 8 Jan 2013, 17:13)

http://dx.com/p/pl2303hx-usb-to-ttl-con … ule-149859