UART/USB interface and you have to check bootloader, connection into a main board of the router - https://wiki.openwrt.org/toh/tp-link/td-w8970

Can I use Serial Com or LPT ?

I read it with usb 232 converter + PuTTY
I got only this Line: y▒▒▒▒Su[▒▒▒▒▒▒▒▒▒ysq▒▒▒▒▒
only power Led is ON , nothing else , there is no Lan when connect to pc

I used usb to ttl 3.3v
GND- Rx - Tx
I got nothig !

Looks like chip without bootloader, memory is empty.

in this case what can I do !?

De soldering chip from router and new programing

how I Can Request New Chip ?
I thinking about replace old chip with new one ready

Hello, Sorry for reopening the topic again, I have the same Router and seems my problem is same, only power light is on and when I connect Lan 1 or Lan 2 to Laptop, Their light turn on but the rest of them are off and reset button doesn't do anything .
I've searched a lot and I bought "CH340G Serial Converter USB 2.0 To TTL" but after connecting the Serial connector to router( GND to GND and RX to TX and TX to RX ) I get black and empty Putty console, I can remember when I connected GND to GND and RX to RX and TX to TX I got some strange codes like this ▒▒▒▒y ▒▒▒▒ , Do you think my memory is empty ? How can reprogram the memory chip with Serial connector ?
It's been 20 days since my router bricked and I couldn't do anything yet, I would really appreciate if you help me about this process.
@jimasek

Do you have correct speed and port COM setup?