Cannot connect to my router

[muzun]

Hello.
I have this https://www.ebay.com/itm/Metal-case...CP2102-STC-PRGMR/222503843286?epid=1250535213

Uart's GND TXD, GND RXD, GND 3V3 is 3.3v

Router
GND-TX 3.3, GND-RX 3.2, GND-3V3 0.0

I connect using Putty

Using the COM number that i get from Computer>Manage>Device Manager
Baud rate 115200
Data Bits 8
Stop Bits 1
Flow Control None


When I connect I get a empty black PuTTY window

 

[kellys_eye]

Swap the Rx and Tx connections

 

[muzun]

Swap the Rx and Tx connections

What do you mean ? Now I connect TXD to RX and RXD to TX and GND to GND, and not using 3.3V and 5.0V.
You mean I need to use TXD to TX and RXD to RX ? or try other cables ? I

 

[muzun]

Router 3.3v pin si giving 0.0
RX and TX are okay

 

[(*steve*)]

You mean I need to use TXD to TX and RXD to RX ?

Yes. This is always the first thing to try when RS-232 is not communicating at all.

 

[kellys_eye]

You do not need to connect the 3.3V line - just the two GND's between devices and the TX and RX lines.

 

[(*steve*)]

You can also use a led and a resistor to determine unambiguously which is the transmit pin.

This varies a little depending on whether you have real RS-232 or a logic level alternative (the latter is most common these days).

Place a 470Ω resistor in series with a pair of LEDs connected in inverse parallel (this simply means you don't have to worry about polarity). Connect one wire to the pin in question and the other to ground. If neither led lights, leave one lead on the pin in question and move the other to the positive power supply. If either led lights in either position, this is an output pin. If it doesn't light then it is either an input or not connected.

Once you have identified the output pins you know what the actual tx pin is. Connect tx to Rx and vice versa. Just to be amusing, sometimes the tx pin is marked Rx because they want you to connect Rx to it.

 

[kellys_eye]

Just to be amusing, sometimes the tx pin is marked Rx because they want you to connect Rx to it.

Doesn't that just hack you off at times.....

 

[muzun]

You do not need to connect the 3.3V line

I know, but is it okay tha 3.3v is giving 0.0v ?

Tried TXD to TX and RXD to RX and vice-versa, same blank window

Router leds are lighting power and if case I connect patch cord it lights too

 

[Alec_t]

but is it okay tha 3.3v is giving 0.0v ?

Sounds like a faulty unit, unless it has some enabling/disabling function.

 

[muzun]

Sounds like a faulty unit, unless it has some enabling/disabling function.

I bricked it when was trying to flash it using SSH, not UART. But leds are working so it's not completely bricked
How do think it will be possible to fix this if I give router to some service center ?

 

[Alec_t]

It will be cheaper to buy a new router than getting it fixed.

 

[davenn]

I bricked it when was trying to flash it using SSH, not UART. But leds are working so it's not completely bricked
How do think it will be possible to fix this if I give router to some service center ?

well you didn't tell us that in your opening post,.
That would have been very helpful info and would have saved wasting everyone's time with the advice Steve and Kelly gave you above.
which was pointless

So you are really dealing with crashed firmware rather than a hardware fault … chances are it is permanently bricked.

time for a new router, and lesson learnt

 

[muzun]

well you didn't tell us that in your opening post,.
That would have been very helpful info and would have saved wasting everyone's time with the advice Steve and Kelly gave you above.
which was pointless

So you are really dealing with crashed firmware rather than a hardware fault … chances are it is permanently bricked.

time for a new router, and lesson learnt

Just on other forum they said it's permanently bricked if leds are not working, but if leds are working when you turn it on and connect patch cords then it can be unbricked.
Okay thanks.

 

[(*steve*)]

It's a bit suspicious if the 3.3V pin reads 0V though. This may be by design, or it may indicate a problem.

Perhaps on the other forum you can enquire if this is expected.

 

[totalmedtech]

i suggest you get a multimeter and check some values,it could be an easy fix(trace from the power source check if everything is in one piece)