I have on old TP-Link TL-WR845N router (Chinese variant - looks just like this)
Someone made images for the US version, and wanted to try flashing it. Unfortunately, looks like the Chinese version doesn't want to.
I did the whole pressing reset button for 15-20 seconds while connected via ethernet - nothing. Then tried the TFTP method with TFTP64 on Windows - nothing shows up in logs, etc. Then even tried using a CH341A with AsProgrammer -
Error connecting CH341(-1)
This is what the motherboard looks like:
And a zoom-in on the chips:
As shown above, there's really only 2 chips can could be tested - but I could only test the one above the long "winbond" chip. The clips cannot physically fit the other one right of that. And I have no de/soldering skills.
I guess this particular router is junk!!