One thing I experienced with both the functioning as well as the broken K3 was, that the USB gets reset after roughly 15 seconds, even though the reset should happen after 30 seconds. I tried quite a lot with the functioning one including pressing vol- after 15 seconds and realsing power while keeping it held for another 10 seconds and also keeping it fixed for the whole dump try. The functioning one simply does not dump even a dump
Some timings in seconds would really help noobs like me (how long to hold the powerswithc until the Vol- gets pressed, how long to hold the vol- with the power switch and how long to hold the vol- after releasing the power switch)
edith: just managed to dump 100 bytes with the working one....
held the power button for 16 seconds, green light switched to orange, held it with the vol- together 1 second, released it and held the vol- for another second.
now dumping from 0x00000000 to 0x08000000 and seems to go really fast (2/3 done in about 5 mins)
Also noticed that on the broken on it does not show the flash capacity (bottom right in ATK) Could be that the meory in the broken is damaged.