Problem to install with uboot prompt

I have a TP-LINK w8970 (v1.2 with lantiqchip) and I am trying to install lede by serial. I started screen and minicom, I see the boot log but I am not able to have the uboot prompt. I press the button "T" on keyboard very quick at poweron but looks like it can't get the input... I have also pressed enter or other random key without succeeded. During the boot I see something like "press enter to activate this console" ... and some other random error to load and/or remove modules... anyway I can't get the prompt.
I have also enable "echo" on minicom to see I press the buttons.. nothing changed..
Any advices ?

For most TP-Link models, copy "tpl" to your clipboard then hit shift-ctrl-V to paste it when the "autobooting in x seconds" appears.

"Press enter to activate this console" is part of the Linux that booted, not the bootloader. It is too late when that appears.

does not work...also at boot I see "press any key to stop autoboot" but does not work..
I have checked the TX pin on serial too.. and looks ok.. I really don't what to do..

my router is not bricked, it has the original firmware. But here a guy says "is hardware handshake disabled ?" ... what means ?

In your terminal configuration, make sure flow control is "none".

On a Linux PC, I use picocom. It works with only a -b option to set the baud rate, the other default options are correct for interacting with a router. Never really understood screen.

Do a loop back test of your serial hardware by connecting the TX and RX wires together without a router. You should see everything you type. When you break the connection you should not see what you type. If "echo" is on (it should not be) you will see everything twice when looped back and once when not.

Some routers do not ship with a physical connection from the TX pin to the CPU. You have to bridge an uninstalled resistor on the board or add a jumper wire. This should be explained on the device's OpenWrt wiki page.

well... I have disabled the software flow control... nothing has changed. The loop back test works well.
This is the page of the device on LEDE and this on openwrt. But both say press t button to enter on uboot. they don't say anything about jumper or strange way to have the uboot prompt..

the following is the boot log of tp-link w8970, thank you.

@saint thanks for sharing the link hope it helps.

IMHO, the router was been hacked and uboot is not the original one.

First of all, I apologize for bad English. The t key does not respond on the w9980 uboot display.
I press the tpl keys. I am copy and paste. but there is no reaction.
so i can't stop the auto boot. I can't enter code.
Trials were done with different usb serial port devices.
When I shorts with the r225 pin, the device switches to UART mode.

also the link is broken