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[HOWTO] [REF] Get Download Mode without 3-button combo using homemade JIG

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TheBeano

Senior Member
Jul 18, 2010
355
216
This guide is for the situation where your phone is not booting and the three-button combo for getting into download mode is not working for some reason, and you have tried all the other solutions in the FAQ. It won't help you if you can already get into download mode but something else is going wrong with the flashing process, for example you can't get Odin to communicate with the phone.

If the phone's bootloader is still intact, that is you see at least the white Galaxy S/Samsung/AT&T logo or the "PC ! Phone" logo on the screen, you should be able to force it into download mode by connecting a homemade jig that simulates the Samsung "Anyway" field test jig. You can buy these jigs online, or make them using a micro USB plug and a resistor.

If your phone screen is always black, that is it does not display the white Galaxy S/Samsung/AT&T logo when you switch it on, then sorry, this jig will not help you.

If this helps you recover your bricked phone, please donate to the CyanogenMod developers: go to this thread and click the link under "SUPPORT US". Thanks.

If you don't want to buy a pre-made jig, you can build one yourself from a few parts. You will need:
1. a micro USB plug that you can solder onto. If you are not confident with soldering or you just want a tidy solution, buy this micro USB breakout board from Sparkfun.

Otherwise, get a cheap micro USB cable and cut the sleeving off the plug with a sharp knife. You cannot just wire onto the cable because this jig uses a normally-unused pin (pin 4) of the micro USB plug which will not be connected to the cable.

2. a 301k resistor. You can buy one from Digikey, or make one up by joining several resistors together in series, for example 3x100k and 1x1k. The resistor value does need to be fairly accurate (I would guess within 1% of 301k) to trigger download mode. 300K seems to work for everyone so far.

Procedure:
1. Solder the resistor across pins 4 and 5 of the micro USB plug. Do not do this with the plug plugged in to the phone as the heat could damage the phone's USB socket. The pins are shown in this diagram ("Micro-B"). On the Sparkfun micro USB breakout board they are labelled "ID" (pin 4) and "GND" (pin 5). When the plug is plugged in to the phone they will be the pins closest to the headphone socket.

2. Make sure the phone is fully switched off by pulling the battery, waiting 5 minutes, then replacing the battery. Do not switch the phone on.

3. Connect the rigged USB plug to the phone. Try not to touch the pins on the back of the plug or the resistor(s) as you are plugging it in, as your skin resistance could affect the resistor value seen by the phone. You do not need to press the power button. After a few seconds the phone should go into download mode.

4. Disconnect the rigged USB plug and connect a regular USB cable from your PC to the phone, then you should be able to flash using Odin.

For more information on how this works see this thread and this thread.
 
Last edited:

sackofnoise

Senior Member
Feb 8, 2009
223
3
Quebec
Hi, anyone have pictures of the cable with the resistor soldered? I am just unsure where to solder it, is it on the micro usb cable side or the standard usb (on which end of the cable?) and which part of the cable do you need to cut open? (i heard there is a pin/wire that usually isn't used?)

Also, if i decided to go with the breakout board, i would only have to get the board+301k resistor plugged in the 4 and 5 pin and plug it in the galaxy and would boot in download mode?

Thank you very much!
 

TheBeano

Senior Member
Jul 18, 2010
355
216
I am just unsure where to solder it, is it on the micro usb cable side or the standard usb (on which end of the cable?) and which part of the cable do you need to cut open? (i heard there is a pin/wire that usually isn't used?)

Only the micro USB plug has 5 pins (regular USB plug has 4) so it has to be the micro USB plug. You have to cut the sleeving (insulation) right off the plug. You can disconnect the cable from the plug or leave it attached, but don't plug the other end (the regular USB end) into anything.

Also, if i decided to go with the breakout board, i would only have to get the board+301k resistor plugged in the 4 and 5 pin and plug it in the galaxy and would boot in download mode?

Yes that's all there is to it.
 
Last edited:

MarkyG82

Senior Member
Oct 26, 2010
805
93
Thanks for your reply. I got it working by your suggestion. Seen many others saying leave the battery out for a while and also seen peeps saying do the 3buttonbootwhile inserting the battery.

As my home made jig was soldered with the pins out of the plug I wiggled it/them about in the socket to ensure a connection was made, then I inserted the battery.

Panic over. Flashed JP1 with 512. not been on for long so cant confirm all is working but looks promising.

I am putting this gadget in a !!!!!!S.A.F.E!!!!!! place.

Also will be available for borrowing in the S/SE UK if anyone is interested.

Im gonna leave playing firmware for while as my heart cant take much more at the mo :)

Many thanks to OP and others for various tips.



The short answer is yes :)
 

celtichazard

Senior Member
Apr 4, 2010
305
73
Thanks for your reply. I got it working by your suggestion. Seen many others saying leave the battery out for a while and also seen peeps saying do the 3buttonbootwhile inserting the battery.

As my home made jig was soldered with the pins out of the plug I wiggled it/them about in the socket to ensure a connection was made, then I inserted the battery.

Panic over. Flashed JP1 with 512. not been on for long so cant confirm all is working but looks promising.

I am putting this gadget in a !!!!!!S.A.F.E!!!!!! place.

Also will be available for borrowing in the S/SE UK if anyone is interested.

Im gonna leave playing firmware for while as my heart cant take much more at the mo :)

Many thanks to OP and others for various tips.



The short answer is yes :)

Can you take a pictures of the micro usb soldered and about the procedure or a short video to youtube
 

natao2nv

Senior Member
May 31, 2009
81
5
34
Gold Coast
haha gladly, I've ordered all the parts (i had to get a soldering iron and the whole kit lol).

Haha i have a soldering iron how hrd do ya rekon it will be to make this thing do u rekon it wil boot a non 3 button download on black screen of death ph-!-pc into download mode soo i can get a stick rom back on it i realy miss my galaxy this xperia x10 cost me more but nothing the same haha

Sent from my X10a using XDA App
 

MarkyG82

Senior Member
Oct 26, 2010
805
93
Can you take a pictures of the micro usb soldered and about the procedure or a short video to youtube

Ill see what i can do when i get home. The hardest bit was to make sure the soldered tops of the pins dont touch. Had to redo them a few times. Resistors got hot too but as it worked im confident i didnt bust them.

Sent from my GT-I9000 using XDA App
 

natao2nv

Senior Member
May 31, 2009
81
5
34
Gold Coast
G
Ill see what i can do when i get home. The hardest bit was to make sure the soldered tops of the pins dont touch. Had to redo them a few times. Resistors got hot too but as it worked im confident i didnt bust them.

Sent from my GT-I9000 using XDA App

Looking forward to see this ;)


Sent from my X10a using XDA App
 

vk2vkg

New member
Oct 30, 2006
1
1
Thanks everyone who helped solve this problem. I have a i9000 and flashed it with the captivate rom. I could not charge the phone so I tried to reflash with original software, I used the 803 pit file. It stopped and i waited for about 10 minutes and disconnected the phone and I got the screen of death.

I did this last week and was going to take it to Samsung after the Froyo upgrade came live and I was going to say that it happened when I tried to upgrade.

Guess what I made this USB factory jig and I was so happy that it went into download mode. This made me so happy many thanks and i will wait until the official upgrade comes.

I used a old nokia USB connector stripped the plastic off and bought a 300k resistor from Jaycar for 45 cents and this must be the best 45 cents I have ever spent.
:):):):):):) :) :) :) :D :D :D :D :D :D
harry
 
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  • 70
    This guide is for the situation where your phone is not booting and the three-button combo for getting into download mode is not working for some reason, and you have tried all the other solutions in the FAQ. It won't help you if you can already get into download mode but something else is going wrong with the flashing process, for example you can't get Odin to communicate with the phone.

    If the phone's bootloader is still intact, that is you see at least the white Galaxy S/Samsung/AT&T logo or the "PC ! Phone" logo on the screen, you should be able to force it into download mode by connecting a homemade jig that simulates the Samsung "Anyway" field test jig. You can buy these jigs online, or make them using a micro USB plug and a resistor.

    If your phone screen is always black, that is it does not display the white Galaxy S/Samsung/AT&T logo when you switch it on, then sorry, this jig will not help you.

    If this helps you recover your bricked phone, please donate to the CyanogenMod developers: go to this thread and click the link under "SUPPORT US". Thanks.

    If you don't want to buy a pre-made jig, you can build one yourself from a few parts. You will need:
    1. a micro USB plug that you can solder onto. If you are not confident with soldering or you just want a tidy solution, buy this micro USB breakout board from Sparkfun.

    Otherwise, get a cheap micro USB cable and cut the sleeving off the plug with a sharp knife. You cannot just wire onto the cable because this jig uses a normally-unused pin (pin 4) of the micro USB plug which will not be connected to the cable.

    2. a 301k resistor. You can buy one from Digikey, or make one up by joining several resistors together in series, for example 3x100k and 1x1k. The resistor value does need to be fairly accurate (I would guess within 1% of 301k) to trigger download mode. 300K seems to work for everyone so far.

    Procedure:
    1. Solder the resistor across pins 4 and 5 of the micro USB plug. Do not do this with the plug plugged in to the phone as the heat could damage the phone's USB socket. The pins are shown in this diagram ("Micro-B"). On the Sparkfun micro USB breakout board they are labelled "ID" (pin 4) and "GND" (pin 5). When the plug is plugged in to the phone they will be the pins closest to the headphone socket.

    2. Make sure the phone is fully switched off by pulling the battery, waiting 5 minutes, then replacing the battery. Do not switch the phone on.

    3. Connect the rigged USB plug to the phone. Try not to touch the pins on the back of the plug or the resistor(s) as you are plugging it in, as your skin resistance could affect the resistor value seen by the phone. You do not need to press the power button. After a few seconds the phone should go into download mode.

    4. Disconnect the rigged USB plug and connect a regular USB cable from your PC to the phone, then you should be able to flash using Odin.

    For more information on how this works see this thread and this thread.
    4
    Well we only have one confirmation so far. If it does work for you please let us know what state your phone was in prior to using it as I'm interested to see what problems it can repair.
    2
    There is a tool named Samsung 300K Tool (USB JIG Emulator Samsung 300K) by ScachorroX which can switch many Samsung devices to the Download Mode without physical JIG or 3-buttons.
    It seems tool makes switching trough sending binary service command to the modem diag port, so it should work unless diag port is still accessible (most serious bricks doesn't establish diag port, so you'll need the real JIG or another tools like JTAG-related).

    Author's description:
    Only connect USB Cable to phone ON!
    - Android
    - Bada
    - Qualcomm Cpu
    - Broadcom Cpu
    - Etc :--))

    This old tool discussed here:
    http://forum.gsmhosting.com/vbb/f777/samsung-300k-tool-force-enter-download-mode-via-usb-1718796/
    Links are already dead, so I do attach a copy of the executable here.
    1
    I knew you guys would figure it out - well done. I will build one before I attempt rooting and flashing

    Sent from my GT-I9000 using XDA App
    1
    This is awesome!

    added to the wiki :)