Chinese Tablet: Onda V701s

tablet-onda-v701s-quad-core

I bought this tablet while I was searching to buy one for a kid as a gift. So, it had to be with normal specifications and not highly expensive. And i found this 7″ tablet and bought it new for only 300yuan (less than 50USD) on the first month of 2015.

The tablet specifications are the following:

Honestly, the tablet isn’t bad considering the price.

Problem presented:¬†After few months of use, i noticed that something inside was not really good attached because everytime you flip or rotate the tablet you can hear and feel that something is moving. But i didn’t care about it since the tablet was still working until recently. The tablet only worked with the charger plugged in and immediately shuts off after unplugging the charger. The only possibly hardware reason for this behavior is because the battery is disconnected.

Solution:

It’s very easy to disassembly this tablet. This model is different with the V701 (For this model, follow this guide: https://www.ifixit.com/Device/Onda_V701)

  1. Plug your tool between the screen and the back plate as seen in the picture. In the side of the connectors and buttons, there is little tiny hole there.img_20161023_160541
  2. Use the other tool to help you detach slowly this two pieces. Don’t press the screen with your hands since damage it by pressure. Take the screen by the borders.img_20161023_161242
  3. And finally open. As I suspected, the battery wasn’t fixed. The manufacturer only used a little and tiny glue and it already took off.img_20161023_161333
  4. As suspected, because of the detached battery, the cable  (red) broke.img_20161023_161400
  5. Solder it again. Caution: Since a battery is sensitive to temperature, solder it quickly when you are making contact between the cable and the tin. Don’t make contact between the black (negative) and red (positive), this will cause a short circuit and will damage your battery.img_20161023_162402
  6. Take this chance to fix the battery with black insulating tape.
    img_20161023_165553
  7. Put back the back plate with pressure to the screen. And finished!

img_20161023_170208

Additional info: I suggest not to update/change the firmware if the tablet is working correctly. There is no need in doing so. If you need to reinstall the firmware for any reason. You can download Android KitKat 4.4.2 stock firmware for Onda V701s tablet from here or from here. (I didn’t uploaded them, and cannot indicate the original source since i found it on several sites). Or you can download the firmware from the official page I indicated at the beginning.

Firmware details
Archive name: V701s Core4_V1.0.1_V9
FW version: Android KitKat 4.4.2 stock

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Repairing a Sony Xperia Z1 Compact

To start, i will point out the relevant specifications of this smart phone, the Sony Z1 Compact (D5503):

  • Launched: January, 2014
  • Dimensions: 127 x 64.9 x 9.5 mm
  • Weight: 137g
  • Display size: 4.3″
  • CPU: Quad-core 2.2 GHz Krait 400
  • GPU: Adreno 330
  • Camera: 20.7 MP, LED flash
  • Battery: Non-removable Li-Ion 2300 mAh battery

Problem presented: The cellphone in less than two months of use started to have the “Ghost/Phantom touch” problem. See this video:

It was useless after trying the calibration methods. The phone user tried to disassembly the lcd by himself but broke some borders of the lcd and a signal connection of its back. After that, a new lcd was installed but it was unresponsive.

Solution:

Before trying to do a disassembly or hardware fix, it is better to discard and run out any software fix.

Since, even Sony officially reported issue with Z1/Z1s touch screens and a fix would be released with Android 4.4 update. See here.

Follow this steps to verify the software:

  1. Download Sony Companion software.
  2. Do a backup to your computer of all your important files/photos/videos/contacts. Everything you think it is valuable for you. This is in case the update fails or the update doesn’t go out smoothly.
  3. If the software tells you there is an update, do the software update. If you already have the latest version, go to next step.
  4. Do a software repair. This will erase all your data, so do step 2 first.
  5. If the problem persists, let’s go to try with the hardware.

The following video is a disassembly of the phone back part in case you need it. You don’t need to do this. Only for reference.

Source

We need to follow this video to disassembly the lcd. Take note that the glue is located around the borders and most at the top and bottom part. There is no need to heat the center.

Disconnect the lcd from the flex connector using a plastic tool.

IMG_4a
Figure 1 LCD flex connector (this photo was taken after the replacement)

We must check this flex connection located at the back of the LCD. This figure 2 shows that the connector was separated from its board (this is the broken LCD). This happened due to a bad disassembly.

IMG_11a
Figure 2 Broken flex connection

After doing the replacement for the new LCD. I turned on the phone and discovered that the screen was totally unresponsive. So i turned off and checked the LCD again. The problem was that this flex connection of figure was not properly connected.

IMG_6a
Figure 3 Flex cable connection

So, using a plastic tool, lift the connector up (black part) as seen in figure 4. You must lift it from the opposite side of the connection.

IMG_5a
Figure 4 Connector up

After that, disconnect carefully the cable and connect it again very carefully. Verify that the whole terminal (pins) are totally inside the connector. And lift down the connector (black) securing it. Connect the LCD to the main board and turn on the phone to test it.

IMG_3
Figure 5 Testing the LCD

Finally, the LCD was working normally. So, I tried for a few days before glueing it.

Disclaimer: All youtube videos aren’t mine. They are property of their respective authors. But all the photos are taken by me.