codestruct blog

Unboxing the Tehnoetic S2 phone with Replicant


For some years I am using a second-hand Huawei Ascend Y200.

Hardware specifications: 800 MHz CPU, 256 MB RAM, 512 MB Flash memory, 2 GB SD card, 320 x 480 screen resolution

Dimensions: Height 116.9mm, Width 60.4mm, Depth 11.7mm, Weight: 120g (including battery)

Software overview:

  • Pre-installed Android 2.3
  • I did not connect to a Google account but there are quite a few non-free and non-uninstallable apps present
  • Apps via F-droid store
  • Kontalk messenger

Backup strategy: USB storage connection to PC for some data but not all. No regular backup of contacts.

Recently, the hardware got some glitches which resulted in a situation where I could not install new apps or update existing ones. Also the USB to PC connection stopped working.

Even before, I could not some apps because of the limited flash memory and the fact that certain useless apps are forbidden to uninstall.

Looking for a new phone

My requirements for a new phone are:

  • Fair hardware (which includes the production chain, open hardware specifiations and being as robust as possible to reduce electronic waste)

  • Free software


I wanted a phone that works pretty much out of the box without having to worry about hardware compatibility and installation hassles since I never used Replicant before. The only shop and product I found to meet these criteria was the second-hand Samsung S2 by Tehnoetic. The Romanian shop was positively mentioned by the FSF so I decided to test my trust.

Tehnoetic S2 phone with Replicant

Hardware specifications: Dual-core 1.2 GHz Cortex-A9 CPU, 1 GB RAM, 16 GB internal storage, no SD card installed, 480 x 800 screen resolution. This is really better than the old phone.

Dimensions: 125.3 x 66.1 x 8.5 mm, Weight: 116 g (probably including battery)

Software overview: pre-installed Replicant 4.2 0004 (based on CyanogenMod, based on Android 4.2), default app store F-droid.

Ordering and Shipping

Before I placed the order, I had some questions which the shop owner answered timely, friendly and comprehensively.

The payment was done via bank transfer to the given Romanian bank account.

The estimated delivery time of 4 - 7 business days could not be met but I was notified about this issue via email.


The phone was located in an original-looking Samsung soft box which smelled of cold smoke. Something that has to be accepted when buying second-hand, I thought. Gladly, the phone itself had no smell at all.

Switching it on (part 1)

The power button did not work at once but I remembered some note that the battery is taped off due to shipping regulations.

Switching it on (part 2)

(Still no SIM card inserted)

After having removed the battery tape the phone started up. A few things I noticed:

  • Fast boot time (< 30 seconds)
  • Tidy app menu. Only about one screen full of pre-installed apps. No junk apps. No Google apps.
  • The time is not set and auto-configuring does not work because there is no network connection yet.

First actions:

  • Disabled some built-in apps like "Mail" just to try it out
  • Opened the F-droid store => no apps installed.
  • Browse through the pre-installed wallpapers, ringtones and other menus
  • Configured the lockscreen
  • Disabled keyboard sound
  • Tried the Terminal Emulator app (cool to have access to a shell)
  • Made a picture with the camera
  • Connect with USB cable to computer

Screen protector and branding

The screen protector did not look nice so I removed it using these simple instructions. Note, that the installed protector was good non-mirroring in contrast to the one from the video.

On the shop screenshots the phone is branded with the "TEHNOETIC" logo. My phone however has the standard "SAMSUNG" branding.

Reboot options

When you choose "Reboot" from the menu (and in the Developer settings - which were on by default - the "Advanced boot options" option is checked) then you get three options

  • Reboot -- default
  • Recovery -- reboots and goes into the clockworkmod shell which can be used for backup and recovery; I don't know yet for which use cases this should be used
  • Download -- reboots and goes into some Download mode which did nothing until I pressed the power button long to turn the phone off.

Note, when you accidentally disable the Developer settings menu it can be restored by tapping 5 times somewhere as described here.

Connect with USB cable (part 1)

There are several options: the default one is to act as MTP device. Another one is the USB storage device which did not work and the KDE device notifier repeatedly showed up and disappeared as if some logic tries to connect but fails. I then used MTP to transfer two songs in ogg vorbis format and was able to play them with the pre-installed Apollo app out-of-the-box.

I also briefly opened a remote shell using the Android Debug Bridge (adb) from my openSUSE host.

NEXT: Connect to the Internet without SIM card and Wifi

Wifi and Bluetooth are both not working with Replicant because there is no existing free firmware yet that works with the given hardware.

I will report back about how to connect to the Internet without SIM card but using an USB cable.

Read Part 2 of the Replicant user review.

TODO: include discussion capability to this blog post.