Why does the usb-ttl adapter stop working when flashing the tl-mr3020 router via ttl?

Question

USB

In general, the story is this, I installed the openwrt web interface on the tplink mr-3020 router via the web. I rummaged through the settings)) and messed up this device (it’s impossible to access the router via the web to the ip I set)
And I decided to reflash through the TFTP server following this instruction again:
wiki.villagetelco.org/Serial_Port_Access_and_Firmw...
(if I I translated everything correctly, then the instruction should have helped in this matter)
2 such devices were purchased:

When turned on in usb, they had a red diode on.
then I clung to the router:

And all the lights assigned to it (green ones) blinked on the routers.
Then I made the settings through the GtkTerm interface as indicated in the instructions:

and then I kind of started to appear tex in the GtkTerm terminal, as it was said in the instructions.
And then, in an attempt to catch and enter tpl in the GtkTerm interface, for the third time I interrupted the loading of the router, which did not wait for the end, and the usb-ttl adapter stopped working for me (the red diode is not lit, but power is supplied)
Then I took the second same device and removed everything went even faster. The router just started to boot and the text in GtkTerm began to appear in the terminal, but then the adapter died again and the same situation. I sort of did the pinout correctly several times.
And yes, the GtkTerm program, when you turn on the port of the usb-ttl adapters, after all, does not find / dev / ttyUSB0.
I got the feeling that the whole thing was very hot because I took it with my hands, and even if right now I connect a router through these usb-ttl adapters (I’ll say it again, the red diode on the adapter doesn’t work, but power is supplied to the router), then the square chip on the router starts to get very hot .
And the question is, what am I doing wrong, Or am I not to blame and I just have adapters (taken on Ali Express) clumsy? Or do you just need to supply power through some kind of current limiter? well, or I don't know)).
I tried to somehow describe the whole situation in my own words, don’t get angry if anything)) I don’t do such things so often)) I don’t quite understand many things.

Answer 1

Once I also tried to restore one of the routers with this adapter and almost pulled out the hair on my head ...
I have a programmer for this purpose ...