If you’ve hard bricked your Galaxy S2 (and can’t get into download mode) or you want to reset the ODIN download counter (so no one will no you’ve rooted your Galaxy S2), or you just simply
want to remove the i9100 splash screen, you can make a USB jig to solve all your problems.
What is a USB jig?
USB jig is a simple circuit that allows you to reset the download mode and also get into it for Samsung smartphones (can work on other Samsung phones besides the Galaxy S2) just in case something goes wrong. On a hard brick, this can save your phone as it will enter into download mode. Think of it as a reset switch.
You can buy a USB jig on Amazon for around $6-10 or for about $2, you can make your own. It’s a really simple circuit that involves putting 300K Ohms of resistors between pin 4 and 5 of the microUSB connector.
Here’s how to make your own for $2!
Step 1. Cut the micro USB connector off your micro USB cable.
Step 2. Start taking off the plastic on the side with heavy-duty scissors or knife until you get to the metal bones.
Just cut it all the way until you can access all FIVE pins.
Although every microUSB connector is different, mine had all the pin soldered except for pin 4 (which is shown by the arrow below), this is the pin that’s unused, so it was easy for me to identify. You need to connect a resistor in between this pin 4 and pin 5. Pin 5 is located to the right of pin 4.
Below is what the pins look like for microUSB:
Step 3. You will need resistors, I am using 100K Ohm resistors I bought at Radio Shack.
Step 4. Since the pins are so darn small, it’s going to be rather hard to solder the resistors right onto it. So I got 2 insulated wire pieces and solder them onto the pin 4 and pin 5.
Step 5. Below shows my wires soldered securely onto pin 4 and pin 5.
Step 6. Since I don’t have a 300K Ohm resistor, I am simply going to put three 100K Ohm resistors in series and solder them, this is actually pretty fun to do.
Step 7. Last step is simply soldering the resistor piece onto the wires and voila, USB Jig is done. It took me about 15 minutes at most and I haven’t soldered for around 3 years so not too bad so long as it works. You can make it nicer by putting some hot glue over it then putting it in a case but I like having bare circuits, I can always make new ones if I break it.
Step 8. Below shows my ODIN download count over 400+ on my Epic 4G Touch Galaxy S2. This is before using the USB Jig.
Step 9. I turn the phone off then insert my new USB Jig, hoping that I did it right the first time.
Step 10. After about 3 seconds, my Epic 4G Touch Galaxy S2 boots up by itself to download mode, my “custom binary download” count reset to zero and says “erasing download information succeeded”. Congrats!
Step 11. I reboot the phone and find the i9100 boot splash gone!
Next I used the jig on my AT&T Galaxy S2 and worked fine. This USB Jig works on all Samsung devices that support it.
By resetting your download mode count, you’ve truly erased any history that you’ve rooted your phone.