User manual

8.4 Frequently asked questions

Q: I power my board, it shows a logo and then nothing happens.

A: This might be due to a number of reasons but it is recommended to try the following:

1. Download latest official image from our wiki (either Android or Debian for SD card), and upload

it to an SD card again. There are instructions how to do it in the other questions below. Try if the

board works now.

2. Check if your power supply provides enough current, try with different/better power supply.

3. Check the USB hub you are using, plug the USB cable directly to the back of your personal

computer, check the USB cable.

4. The board might enter sleep mode very fast (especially if the Android was turned off without the

“Quick Boot” mode being ticked on). Try pressing or holding down the PWR button for a couple of

seconds to wake it up.

Q: I use LCD_CON for video output. There is some screen flickering under Debian. What

could be the reason?

A: This is usually caused by either a loose cable connection or badly configured script.bin. Double

check if all cables are properly connected. Also check if there is a change in the behavior if you

either twist the cables carefully or press different components at the back.

If the above doesn't fix the flickering problem, edit the script bin parameter lcd_io_cfg0 – make

sure that it is set to = 0×10000000 (1×1 and 7×0).

Q: How do I write the Linux image to a micro SD card to use with my A20 board?

A: To write a Linux image to an SD card under Windows we use Win32 Disk Imager:

Download Win32 Disk Imager software

Insert card

Start program

Select file

Click "write"

To write a Linux image to an SD card under Linux:

For instance you have an image with the file name of "debian_2g.img". It would be downloaded to

the SD card connected to a Linux machine using one of the following commands:

# dd bs=4M oflag=sync if=debian_2g.img of=/dev/sdX

# cp debian_2g.img /dev/sdX

where X is the uSD card.

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