[belezao]

Can wr-841ND V8 be Recovered by Jtag?

I have a tplink wr-841ND V8 with serial console lost.
TFTP doesn't work too.
Can be recovered only with jtag?

Cable/ Tools are the same of the broadcom chipset?

[ian5142]

Serial works every time.
Actually serial and TFTP, I have recovered my 841nd v8 using this method.

https://wiki.openwrt.org/toh/tp-link/tl-wr841nd#tftp_recovery_via_bootloader_for_v8_v9_v10_v11

Read that section and the section just above on serial.

[belezao]

Thank you my friend! I know that WHEN serial is working it is possible recover it. But, as I said , serial is lost,I don't have TX and RX signals. I tried find alternative points for them, but I didn't find. It's a friend's router, he tried recover and broke TX and RX pads.

The power led is on but the other leds are blinking all together in a loop of 4 seconds, so I can't use tftp without serial.

I think my alternatives are:

a) find alternatives points to TX and RX of the serial pads ;
b) Maybe use a flash programmer ( I don't have)
c) Try jtag, I don't know if it is possible in Atheros Chip, Broadcom chip I recovered a lot.

[ian5142]

What is exactly wrong with the serial pads? I have never seen a ruined pad. I solder pins on to my routers as needed. I have never ruined a pad or a board.

[belezao]

TX and RX are dead. There were a lot of solder on pads, I cleaned everything, gnd and vcc are good, but tx e rx are dead.

Tests with a multimeter (Resistance)

vcc -- gnd = 1.14k
tx --- rx = open
tx -- gnd = open
tx -- vcc = open
rx -- gnd = open
rx -- vcc = open

[ian5142]

Check the input voltages, from the plug in the router. Find the ground on that plug first, I can't remember if it is the inside of the plug or the outside. With the power on, put the ground lead of the volt meter on that ground. Then probe the serial pads with that ground. You should find 3.3V on VCC. By the sounds of it, the router may be dead.

[belezao]

Router isn't dead, just tx and rx are dead. I have 3.3v in pads, as I said before gnd and vcc are ok.

Router was working with openwrt; router's owner tried update but put wrong file.

Status of the leds are typical for this problem, boot in loop. I recovered many routers in the same situation, but serial pads were OK.

http://www.dd-wrt.com/phpBB2/viewtopic.php?p=751089