RT-AC87U bricked?

[lcb]

Hello,i need the advice for my problem if its possible.
I was using Merlin custom firmware almost 1 year without any problem.One day i disconnect my pc,router etc to clean and when i put all together i had the surprise to see that my router have only the power led on.
If i plug the lan cable on port 1 and 2 its not working,lights are off ,if i use port 3 and 4 i get light for the specific port but i can't establish connection,its says unidentified network.
So no way i can ping the router.I put the router in recovery mode,at least i follow the steps and the power light is blinking slowly ,but because i don't have connection with the router i can't use the rescue from asus.
Thanks

 

[dvohwinkel]

Are you sure your power supply is not going bad?

 

[bsdsource]

A bricked router and hardware failure are 2 separate things. You typically "brick" a router when you improperly flash firmware to the router. You potentially could have hardware failure though. I would try resetting your router to factory defaults and then see if you can ping it. Try removing all LAN cables prior to resetting then after it resets plug in a LAN cable. Also set a static IP on the computer you are using such as 192.168.1.5 (computer) and try pinging 192.168.1.1 (router).

Let us know if you figure it out. Followup responses help others.

 

[gpz1100]

I've had several networking equipment power bricks go bad over the years. Before going through the trouble of factory resetting the device, try a different power adapter first.

 

[lcb]

So i tested with another power adapter from a asus notebook 19V but 3.24A, and i have the same problem.
As i said i cant ping or connect to the router.
With a usb ttl i can debug more?
Thanks

 

[thelonelycoder]

So i tested with another power adapter from a asus notebook 19V but 3.24A, and i have the same problem.
As i said i cant ping or connect to the router.
With a usb ttl i can debug more?
Thanks

Did you do the reset steps as @azdps link says?

 

[lcb]

Yes but its not working,i keep 30 40 sec and nothing its happening.
When i power the router only lan 2 3 4 will light for 1 second, then all are off except power led

 

[bsdsource]

With a usb ttl i can debug more?

Quote on twitter from RMerlin what he suggests for debugging:

Anything with a CP2102, these are the ones I've had the fewer issues with.

If you are familiar with debugging you should give it a try. Nothing to lose at this point.

 

[lcb]

https://www.snbforums.com/threads/t...d-while-flashing-from-tomato-to-merlin.29077/
i have the same symptoms as this guy,so i will give a try.
i ordered this one https://www.amazon.com/dp/B01CYBHM26/?tag=snbforums-20, tomorrow should be here.
thanks for you help guys,i will update the post with new info

 

[lcb]

So,i install drivers for this USB TTL windows 10 recognize from here https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
I follow the steps but my putty session its stuck,at least i don't see anything.
Its something else what i miss?
I use only TX and RX in cross mode.I should use +3.3V also?my adapter have +3.3V and 5V
Thanaks

 

[RMerlin]

So,i install drivers for this USB TTL windows 10 recognize from here https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
I follow the steps but my putty session its stuck,at least i don't see anything.
Its something else what i miss?
I use only TX and RX in cross mode.I should use +3.3V also?my adapter have +3.3V and 5V
Thanaks

You must also plug the ground. Do not plug any of the Vcc lines. Serial parameters are 8N1, 115200.

 

[lcb]

I plug also the ground,forgot to say that.
The settings for putty are as you said.but its all black.if i let speed 9600 then i see like a encrypted msg for 5 6 seconds then its stop.

 

[RMerlin]

I plug also the ground,forgot to say that.
The settings for putty are as you said.but its all black.if i let speed 9600 then i see like a encrypted msg for 5 6 seconds then its stop.

It's probably noise if you see random characters when using 9600.

If you want to test your serial cable, unplug it from the router, short TX and RX, then try typing text in Putty - it should echo back.

 

[lcb]

It's probably noise if you see random characters when using 9600.

If you want to test your serial cable, unplug it from the router, short TX and RX, then try typing text in Putty - it should echo back.

yes i can type now in the putty window,thanks so now i am 100% sure that adapter work.

 

[Fitz Mutch]

I use only TX and RX in cross mode.I should use +3.3V also?my adapter have +3.3V and 5V

Yes, the TX and RX pins use +3.3V TTL signal.

 

[lcb]

Its the same if i connect +3.3v or no,i start to believe that its a hardware problem.the merlin fw was ok almost 1 year.i unplug the router and after aprox 30 min when i plugin in again was not working anymore.
I do the steps to put him on recovery mode,unplug-press reset-plug in-wait 30 sec holding the reset and power led its flashing,so in theory its in rescue mode,but i can't ping or access the router.
For some reason Lan 1 its dead dead,i never saw lighting,when i power the router only Lan 2 3 4 will light for 1 second,then i have light only on power led,wan and wps are lighting also but very very slow.
I use J3 connector for the serial,but what its the JPD1?(its on the other side of the pcb)

 

[Fitz Mutch]

Its the same if i connect +3.3v or no,i start to believe that its a hardware problem.

Do not connect the Vcc pin. I was just saying that +3.3V TTL means that binary "1" is 3.3V, and binary "0" is 0V. If you got a 3.3V/5V jumper on your USB-to-serial adapter, make sure it's on 3.3V.

If you have an oscilloscope, you can watch the TX and RX pins to verify that it is 3.3V TTL signal.

Be sure GND is connected, and use a shorter cable to reduce the noise.

EDIT: also I think the router serial port is always 115200, N,8,1

 

[RMerlin]

One peculiarity I often encounter with Asus routers: plug the USB adapter to the router only after your powered the router on. With at least the adapters that I use, the router will fail to boot if the USB adapter is already plugged in. Not sure if it's an adapter, a router, or a power issue (this house's electrical grounding is pretty much crap).

 

[lcb]

No way,its like he don't even boot.
Usb port from router should work?i ask because i plug a usb drive and no light on my usb drive,i test both 3.0 and 2.0
just as observation, leds from lan ports are brighter compared with the power led

 

[RMerlin]

I never checked if USB ports were getting initialized while in the CFE.