I have a 3 s1, it has the original firmware. the microsd port is broken as in the spring is gone, BUT I have found that if I insert it just enough the screen will say that the SD card is inserted. I can then see all the files on the SD card. I have the f4 chip and I have gone thru the instructions, but it will not flash. It can see the files and folders, but it will not flash I dont know why it wont read the folder and the .bin file. I have renamed the .bin file to my dog.bin and it wont flash, BUT it will read the files on the card. I also have cleaned the card, reformat, used different cards.... same behavior
anyone have any suggestions?