How to Fix “E: Can’t mount /sdcard/” on Smartphone

Android is really a great operating system with immense flexibility and that is why it is the most popular platform in the world. Owning an Android device gives you access to millions of amazing apps and, if you are an adventurous user, also lets you flash custom ROMs, kernels, mods and ported apps via a custom recovery.

There is a huge custom development community that keeps toiling for giving us stuff that enhance our mobile experience. Involving in such activities might add some adventurous flair to your mobile experience but, at the same time, they might also pose issues and risk to the device. Nobody would like to turn his/her phone into a costly paperweight and that’s why one should always take utmost care while flashing custom ROMs, mods and kernels.
Anyway, if you are addicted to flashing mods and ROMs on your Android device, or even if you are a novice to such things, and happen to encounter SD card mount issue in recovery, we have come with some possible solutions to fix the problem. When the error occurs, you might see one of the following messages on the recovery screen:

• CWM can’t mount SD
• SD Card Not Mounted
• Can’t mount external micro sd-card
• SD card won’t mount
• Can’t mount sdcard
• Can’t mount emmc
• Can’t mount external micro sd-card
• E:Can’t mount /cache/recovery/command last_log emmc external micro sd-card
• E: Can’t mount /sdcard/
• E:failed to mount /sdcard (file exists)
• E:failed to mount /sdcard (no such file or directory)

 
 Download this: SD Formattor
 https://www.sdcard.org/downloads/formatter_4/
 

Method 2: Update CWM or TWRP Recovery

Formatting the SD card did not help you at all? Don’t worry, this might be a recovery related issue! Just download the latest version of CWM/TWRP recovery and flash it. You can also try switching to a different recovery than installed on your device. In other words, if your device has CWM, try TWRP and vice versa.
Download ClockworkMod Recovery
Download TWRP Recovery

Flashing ROMs When SD Card is Not Mounted

If you got an urgent need to flash a ROM but after booting into CWM PhilZ recovery are not able to access the external SD storage because of E: Can’t mount /sdcard/ issue, there is still a way you can install the ROM using ADB commands. Here’s how:

1. Set up Android SDK (ADB and Fastboot) on your computer. Alternatively, you can download the minimal Fastboot tool and unzip it.
2. Now copy the ROM zip file to the platform-tools or mfastboot-v2 folder.
3. Get into CWM recovery mode.
4. Make sure that USB Debugging is enabled on your phone. Just to make sure that you device is detected by ADB, connect you phone to computer, launch a command window from the ADB and fastboot folder and type the following command:

   adb devices

5. If you see your device’s serial number in the command window, you are good to go.
6. Now type this:

   adb shell

7. You should see “#” (hash) somewhere in front of your command line.
8. Now type the following command and press Enter key:

   ls

9. Now you should show you the folders on your device. Try to navigate to the directory /data/media using the following command:

   cd /data/media/

10. Now push the ROM file to the above directory via the following command (replace ROM.zip with the name of your ROM file):

    adb push ROM.zip /data/media/ROM.zip

The ROM file will now be installed to your phone and it should boot properly. This tip can be helpful if your device gets into bootloop and you are not able to access your ROM backup or flashable Zip on the SD card.

手机信号G、E、O、3G、H、H+、4g含义科普 你知道吗？

用过安卓手机的都知道，信号显示哪经常有手机信号G、E、O、3G、H、H+、4g的之类的数字，而经常会变，今天小编告诉你安卓手机里的G、E、O、3G、H、H+、4g之类的含义。

G  指GPRS，是2.5G网络（iPhone显示O）；
E  指EDGE网络，属2.75G；
3G 指普通3G网络，速度在2-7M；
H  指3G的升级版hsdpa网络，是3.5G，速度可达14.4M；
H+ 是hsdpa的升级版hspa+，是3.75G，速度可达21M-42M。
4g 技术支持100Mbps~150Mbps的下行网络带宽。4g意味着用户可以体验到最大12.5MB/是~18.75MB/s的下行速度。

网络速度从慢到快依次是G
PS:上面说的速度都是理论速度。实际影响的因素有很多，所以一般都不会稳定在最大速度。

Qualcomm Snapdragon 200, 400, 600, 800 CPUs

Source: Darren Yates 30 June 2013

US ARM-class chip maker Qualcomm produces some of the hottest ARM processors on the market and its no surprise that any smartphone maker worth its salt is lining up to get hold of Qualcomm’s Snapdragon CPUs for its products. But with so many different options available, it can be a bit of a nightmare trying to figure out what’s what.
So in this roundup, we’re going to look at the Snapdragon 200, 400, 600 and 800-class ARM processors to see what makes them tick. We won’t delve into the architecture but we will look at them in a way that makes it easier to tell them apart when you’re trying to decide between phones.

Qualcomm Snapdragon 200
The Snapdragon 200-series is the entry-level ‘newbie’ range of the new family.
So far there are six different Snapdragon 200 CPUs – the MSM8225Q, MSM8625Q, MSM8210, MSM8610, MSM8212 and MSM8612.
Rather than concentrate on each model, we’ll break them down into the differences.
The Q-series are actually older ARM Cortex A5 designs, but quad-core and clocking at 1.4GHz. They’re manufactured on a larger 45-nanometre scale so they’re cheaper to make, but not as power efficient. They use the entry-level Adreno 203 graphics core.
The 8×10 series (dual-core) and 8×12 models (quad-core) are based on the newer Cortex A7 design, all clocking at 1.2GHz with faster Adreno 302 graphics. They’re manufactured at a smaller 28nm scale, so they’re more expensive to make but more power efficient, which should help with producing good battery life.
The Snapdragon 200 series was only announced recently and will be used in entry-level smartphones.

Qualcomm Snapdragon 400
The 400-series is the most plentiful in numbers with ten on offer – we’ll keep this short and just use the basic model numbers: 8226, 8626, 8926, 8230, 8630, 8930, 8030AB, 8230AB, 8630AB, 8930AB.
The 8×26 range are quad-core Cortex A7 designs with up-rated Adreno 305 graphics cores, all manufactured at 28-nanometres and clocking at between 1.2 and 1.4GHz.
The 8×30 series are dual-core but are the first to utilise Qualcomm’s own custom Krait CPU design. Qualcomm is one of the very few ARM license holders that pumps out its own architecture. The Krait design conforms perfectly to the ARMv7 instruction set but does it differently to the reference ARM Cortex design. And this is first CPUs where the Qualcomm ‘special sauce’ comes into play. These chips are based on the entry-level Krait 200 core design, but otherwise share the 8×26 features such as 28nm manufacture and Adreno 305 GPU core.
Finally, the the four AB-series chips all use the uprated Krait 300 core design clocking up to 1.7GHz, again in a dual-core arrangement, manufactured at 28nm and with the Adreno 305 core.
The Snapdragon 400 series is expected to appear in mid-range phones in the next 12 months.

Qualcomm Snapdragon 600
For most of 2013, the Snapdragon 600 series has been the flagship Qualcomm CPU range, appearing in some top-drawer smartphones including the HTC One and Samsung Galaxy S4.
At the moment, there are only two in this series – the APQ8064T and APQ8064M. Again, these are both manufactured at up to 28nm and run the faster Adreno 320 graphics core. The main difference is the T chip runs at up to 1.9GHz, while the M model tops out at 1.7GHz. The T also includes integrated Wi-Fi and Bluetooth while the M doesn’t. Basically, these are quad-core versions of the Snapdragon 400 but include the faster Adreno 320 GPU.

Qualcomm Snapdragon 800
The Snapdragon 800 is now the new flagship ARM CPU until we see the the first 64-bit Cortex A57 chips some time in 2014. They use the new Krait 400 core design, clocked up to an impressive 2.3GHz. They all run the fastest Adreno 330 GPU core, they’re all manufactured at 28nm, they all have integrated 802.11a/b/g/n/ac Wi-Fi and Bluetooth 4.0. The difference? The modem. The 8074 comes with no data connectivity at all; the 8274 is the HSPA+ (3G); the 8674 supports CDMA networks; and the 8974 is the next-generation 4G/LTE option.
So far, the first phones announced using these chips are the Samsung Galaxy S4 LTE-A model and Sony’s Xperia Z Ultra. Reports also suggest Microsoft showed off its up-coming Surface RT tablet using a Snapdragon 800 series CPU at its recent Developer’s Conference. This will be an interesting test to see how well the Snapdragon Krait core compares with Intel’s X86-architectured Atom CPU in a Windows environment in terms of productivity speed.
So that’s a rough snapshot of the new Snapdragon series – as I said, it’s not a full-on view of the architecture difference but it should be enough for you to understand just what you’re picking up the next time you go to buy a Qualcomm-powered smartphone from your favourite brand.