Samsung UART - Prototype Board - Hardware Hacking Series #8

In this video I solder the headers, variable resistor, and wires onto the prototype board. It was an interesting experience, as this was the first time that I had actually made something with a prototype board. Stay tuned for the next video where I'll demonstrate the finished and home-made Samsung Anyway device.
Special Thanks:
- Josh (First elite supporter!)
Warranty Disclaimer: Accessing the UART console on your Samsung device may void the warranty and in some cases even brick your device (i.e. make it unusable).
Safety Disclaimer: Soldering irons are tools that should be handled properly as they can easily cause injury. Soldering thread containing lead is toxic and should not be exposed to open wounds. If you do a lot of soldering, then you should consider wearing some thin gloves. (Not plastic!)
Always wash your hands after handling lead. If you're going to eat something while soldering, then wash your hands first. Keep food and drinks away from your working table too.
Lead-free solder thread is not without risks too, as it's harder to use, and the increased fumes it may produce are in return more toxic. Consider using a fume extractor if you do a lot of soldering.
Soldering Iron:
- Velleman VTSS4N (www.velleman.eu...)
Soldering Thread:
- 60Sn/40Pb (60% Tin / 40% Lead) 0.6mm with rosin/resin core (www.velleman.eu...)
Stay tuned and subscribe for more upcoming videos showing actual hacks!
Twitter: @CrazyDaneHacker
Facebook: / crazydanishhacker
Patreon: / crazydanishhacker
Website: www.crazydanis...

[@saultes]

As always, nice video. If I may suggest something for the cables, heat shrink help a lot especially when cables are thin and the mechanical connection to the connector is not great.

[@CrazyDanishHacker]

Thanks, it did end up working :-)

[@RupeshSingh-ug1xe]

I cannot find micro usb with id pin out to ground it. Where can I find micro usb with id pin out. All the micro usb data cables I buyed in local market has only four pins out (id pin excluded).

[@samirgunic]

Get a microUSB to microUSB OTG cable. That's what I did. It's a cheap and short cable, no longer than 20 cm. I cut it in half and used the straight end marked "HOST" to wire up to a breadboard. The second half of the cable has ID and GND wires connected on the ID pin of microUSB connector, and no connection on GND pin. So this half of the cable is not what you want to use for this project. You need a wire going to the GND pin. You could possibly wire it differently, but it's best to avoid mistakes by following the appropriate pin-out and color scheme. Colors alone are not to be trusted though, but in my case the colors did follow the correct USB standard colors: red, white, green, brown, black. Brown is the ID wire/pin. Alternatively, you could get a microUSB "breakout board", if you can find a male version that is. I purchased the female variant of this, just in case. I didn't think it through when I ordered my supplies. But it seems male microUSB breakout boards are almost impossible to source. I did see that SparkFun has one variant of that, for anyone interested, and who can order SparkFun products.

[@Aali4500]

Hey , thanks for your tutorials , i damaged my device(an old modem) because of editing some file in the serial terminal ... can i do sth for restore it back ? sth like hard reset (also the reset button doesn't work ) or restart its memory ?

[@CrazyDanishHacker]

The reset button on the device is usually monitored continuously during normal operation mode. However in your case, it sounds like there's a failure at startup. Try disconnecting the power from the device a few minutes, then hold the reset button and plug back in the power, and then press the power button while still holding the reset button for a few minutes before letting go. If that doesn't work, try and disconnect the power again and this time instead of holding the reset button try and press it every few seconds during startup in hopes of that you will trigger a recovery procedure. Assuming you've already tried to undo the change you made in the serial terminal, there are a few more advanced steps you can try. Option 1: Dump the entire firmware from memory. Some devices have two copies of the firmware. (One for backup / restore and one for normal operation mode. Use the backup to overwrite the normal op mode files.) Even if the modem is broken you can usually get into the first boot environment where you can try to dump firmware from memory, write to memory and some configuration files, and also in many cases install firmware. Option 2. Discover the hidden firmware update method on your device. A lot of devices will actually look for a specific IP address during startup and if that is available, then the device will try to download a firmware file from the IP address and install it. Finding this information is sometimes present in the first boot environment. If not, then you will need to dump the firmware from memory and search for IP addresses with e.g. a regular expression at locations that are likely to contain the code for firmware updates. A good place to look is close to where you can find strings from the first boot environment. Option 3 - Super Advanced: Dump firmware from memory using a SOIC clip, I recommend using an original Pomona clip. Analyze what you need to change in the firmware to fix the device by e.g. using the serial terminal through UART, or by running the firmware inside QEMU as an emulated device. Getting it to run QEMU can be very time consuming and tricky. Now once you've fixed the firmware, install it onto the device through either the first boot environment, or if that doesn't work, try and write it directly to the flash chip. Alternatively, buy a chip that has the exact same pin layout and functionality as the original flash chip and then install the firmware onto that and then solder it onto the device. Before you do any of the steps that require a lot of work, I recommend trying to analyze what the exact root cause of the problem is and if you can fix it with a small update or change in e.g. the first boot environment.

[@Aali4500]

@@CrazyDanishHacker Thank you the modem doesn't have the official brand and also is old maybe i can not find the firmware ... as i recognized the serial port show nothing and when i was in the section of changing number of mac add (after seeing this page i manually powered off the modem without submitting anything) happened and modem in the first step looking for bootloader as you said .... any of the techniques you mentioned needs about 1 week to learn and run:))) ... but anyway i will try all of them and again thank you for your response ...

[@samirgunic]

@@CrazyDanishHacker Now that's a proper, professional, detailed and respectful answer. Not really related to the video though, but really helpful. I don't come across this kind of respectful and enthusiastic response very often, with willingness to help. Even when someone barges in, crashes the course, steals the show, and steers the conversation off topic just to cover their own personal needs. That's very admirable.